Films and bags with visually distinct regions and methods of making the same

ABSTRACT

One or more implementations of a multi-layer film include a first substantially un-pigmented layer non-continuously bonded to a second pigmented layer. The multi-layer film includes an unexpected appearance differing from the appearance of the pigmented layer. In one or more embodiments, the multi-layer film includes a metallic appearance despite the pigmented layer being devoid of metallic pigment. The multi-layer film also includes areas that are visually distinct from areas of the film with the unexpected appearance. The visually-distinct areas comprise areas in which the first substantially un-pigmented layer non-continuously bonded is in intimate contact with the second pigmented layer. The visually-distinct areas have the appearance of the pigmented layer. One or more implementations also include methods of making multi-layer films and bags with an unexpected appearance and visually-distinct areas.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 13/660,844, filed Oct. 25, 2012, and entitled“THERMOPLASTIC MULTI-PLY FILM WITH METALLIC APPEARANCE.” The presentapplication is also a continuation-in-part of U.S. patent applicationSer. No. 13/299,177 filed Nov. 17, 2011 and entitled MULTI-LAYEREDLIGHTLY-LAMINATED FILMS AND METHODS OF MAKING THE SAME, which is acontinuation in part of U.S. patent application Ser. No. 12/947,025filed Nov. 16, 2010 and entitled DISCONTINUOUSLY LAMINATED FILM andissued on Dec. 10, 2013 as U.S. Pat. No. 8,603,609, which claims thebenefit of and priority to U.S. Provisional Application No. 61/261,673,filed Nov. 16, 2009. This application is also a continuation-in-part ofU.S. patent application Ser. No. 13/838,394, filed Mar. 15, 2013, andentitled “DISCONTINUOUSLY LAMINATED FILM STRUCTURES WITH IMPROVED VISUALCHARACTERISTICS, which is a continuation-in-part of, and claims priorityto, U.S. patent application Ser. No. 13/454,412, filed Apr. 24, 2012,entitled THERMOPLASTIC FILMS WITH VISUALLY-DISTINCT STRETCHED REGIONSAND METHODS FOR MAKING THE SAME, which claims priority to U.S. PatentProvisional Application Ser. No. 61/478,639, filed Apr. 25, 2011,entitled THERMOPLASTIC FILMS WITH VISUALLY-DISTINCT STRETCHED REGIONSAND METHODS FOR MAKING THE SAME. U.S. patent application Ser. No.13/838,394 is also a continuation-in-part of, and claims priority to,U.S. patent application Ser. No. 13/454,474, filed Apr. 24, 2012,entitled MULTI-LAYER FILMS WITH VISUALLY-DISTINCT REGIONS AND METHODS OFMAKING THE SAME, which claims priority to U.S. Patent ProvisionalApplication Ser. No. 61/478,643, filed Apr. 25, 2011, entitledMULTI-LAYER FILMS WITH VISUALLY-DISTINCT REGIONS AND METHODS OF MAKINGTHE SAME. U.S. patent application Ser. No. 13/838,394 also is acontinuation-in-part of, and claims priority to, U.S. patent applicationSer. No. 13/552,352, filed Jul. 18, 2012, entitled MULTI-PLY PUCKEREDFILMS FORMED BY DISCONTINUOUS LAMINATION OF FILMS HAVING DIFFERENTREBOUND RATIOS, and is a continuation-in-part (CIP) of, and claimspriority to, U.S. patent application Ser. No. 13/660,844, filed Oct. 25,2012, entitled THERMOPLASTIC MULTI-PLY FILM WITH METALLIC APPEARANCE,and is a continuation-in-part (CIP) of, and claims priority to, U.S.patent application Ser. No. 12/947,025, filed Nov. 16, 2010, entitledDISCONTINUOUSLY LAMINATED FILM” and issued on Dec. 10, 2013 as U.S. Pat.No. 8,603,609. The contents of each of the above-referenced applicationsand patent(s) are hereby incorporated by reference in their entirety.

BACKGROUND

1. The Field of the Invention

The present invention relates generally to thermoplastic films and bagsformed therefrom. More particularly, the present invention relates tothermoplastic films and bags including multiple layers and uniqueaesthetics.

2. Background and Relevant Art

Thermoplastic films are a common component in various commercial andconsumer products. For example, grocery bags, trash bags, sacks, andpackaging materials are products that are commonly made fromthermoplastic films. Additionally, feminine hygiene products, babydiapers, adult incontinence products, and many other products includethermoplastic films to one extent or another.

The cost to produce products including thermoplastic film is directlyrelated to the cost of the thermoplastic film. Recently the cost ofthermoplastic materials has risen. In response, many manufacturersattempt to control manufacturing costs by decreasing the amount ofthermoplastic material in a given product.

One way manufacturers may attempt to reduce production costs is to usethinner films or stretch the thermoplastic films, thereby increasingsurface area and reducing the amount of thermoplastic film needed toproduce a product of a given size. Unfortunately, stretched or otherwisethinner thermoplastic films can have undesirable properties. Forexample, thinner thermoplastic films are typically more transparent ortranslucent. Additionally, consumers commonly associate thinner filmswith weakness. Such consumers may feel that they are receiving lessvalue for their money when purchasing products with thinner films; andthus, may be dissuaded to purchase thinner thermoplastic films.

To compensate for some deficiencies of thinner films, manufacturers mayadd colorants or voiding agents. Depending on how they are used,however, colorants and voiding agents can sometimes weaken the chemicalbonds in the film, and create a still weaker film. Moreover, the use ofcertain colors in a film structure may present unique challenges, suchas expensive. For example, metallic pigments, which are often thought ofas indicating strength, are particularly expensive. As such, the cost ofsome pigments can counter any savings gained by the use of thinnerfilms. Furthermore, even pigmented films commonly become less opaqueupon stretching.

As such, manufacturers may be dissuaded to stretch a film or use thinnerfilms despite the potential material savings. This is particularly thecase when strength is an important feature in the thermoplastic product.For example, thermoplastic trash bags need to be puncture and tearresistant to avoid inadvertently spilling any contents during disposal.Consumers may be hesitant to purchase bags made from thinner filmsfearing that the bags will fail along the seams or other areas of thebag commonly subjected to stresses.

Accordingly, continued improvement is needed to address the uniqueproblems associated with improving trash bags while conserving the useof expensive thermoplastic materials and pigments.

BRIEF SUMMARY

One or more implementations of the present invention provide benefitsand/or solve one or more of the foregoing or other problems in the artwith films and bags with a unique appearance and visually-distinctregions. In particular, the appearance of the films can providemulti-layers films with a unique metallic or other appearance thatdiffers from the appearance of the individual layers alone. The filmscan be non-continuously bonded together and have regions in which thelayers are in intimate contact. Such regions can be visually distinctfrom the other areas of the film in which the layers are not in intimatecontact. The visually-distinct regions can provide a visual cue to theconsumer about the strength and quality of the film. Furthermore, thevisually-distinct regions can provide a unique and pleasing visualeffect.

Additional features and advantages of exemplary embodiments of thepresent invention will be set forth in the description which follows,and in part will be obvious from the description, or may be learned bythe practice of such exemplary embodiments. The features and advantagesof such embodiments may be realized and obtained by means of theinstruments and combinations particularly pointed out in the appendedclaims. These and other features will become more fully apparent fromthe following description and appended claims, or may be learned by thepractice of such exemplary embodiments as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above recited and otheradvantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof that areillustrated in the appended drawings. It should be noted that thefigures are not drawn to scale, and that elements of similar structureor function are generally represented by like reference numerals forillustrative purposes throughout the figures. Understanding that thesedrawings depict only typical embodiments of the invention and are nottherefore to be considered to be limiting of its scope, the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIGS. 1A-1C illustrate views of various films structures in accordancewith one or more implementations of the present invention;

FIG. 2 illustrates a view of a multi-layer film with areas in which twolayers are in intimate contact in accordance with one or moreimplementations of the present invention;

FIG. 3A illustrates a schematic diagram of two thermoplastic films beingbrought into intimate contact and laminated by MD intermeshing rollersin accordance with one or more implementations of the present invention;

FIG. 3B illustrates an enlarged view of the two thermoplastic filmspassing together through the intermeshing rollers of FIG. 3A taken alongthe circle 3B of FIG. 3A;

FIG. 4 illustrates a view of a multi-layered thermoplastic film withvisually distinct regions created by passing thermoplastic films throughthe intermeshing rollers of FIG. 3A;

FIG. 5A a schematic diagram of two thermoplastic films being broughtinto intimate contact and laminated by TD intermeshing rollers inaccordance with one or more implementations of the present invention;

FIG. 5B illustrates an enlarged view of the films prior to passingthrough the intermeshing rollers of FIG. 5A;

FIG. 5C illustrates an enlarged view of the films passing through theintermeshing rollers of FIG. 5A taken along the circle 5C of FIG. 5A;

FIG. 5D illustrates an enlarged view of the multi-layer film afterpassing through the intermeshing rollers of FIG. 5A;

FIG. 6 illustrates a view of a multi-layered thermoplastic film withvisually-distinct regions created by passing thermoplastic films throughthe intermeshing rollers of FIG. 5A;

FIG. 7A illustrates a view of a multi-layered thermoplastic film withvisually-distinct regions created by passing thermoplastic film throughthe intermeshing rollers of both FIG. 3A and FIG. 5A;

FIG. 7B illustrates a view of another multi-layered thermoplastic filmwith visually-distinct regions created by passing thermoplastic filmthrough the intermeshing rollers of both FIG. 3A and FIG. 5A;

FIG. 8 illustrates a view of a multi-layered thermoplastic film withvisually-distinct regions created by passing thermoplastic films throughdiagonal direction intermeshing rollers in accordance with one or moreimplementations of the present invention;

FIG. 9 illustrates a schematic diagram of a set of intermeshing rollersused to form a structural elastic like film (SELF) by impartingstrainable networks into the film while lightly laminating adjacentlayers of a film in accordance with one or more implementations of thepresent invention;

FIG. 10 illustrates a view of a multi-layered thermoplastic film withvisually-distinct regions created by passing thermoplastic films throughthe intermeshing rollers of FIG. 9;

FIG. 11 illustrates a view of another multi-layered thermoplastic filmwith visually-distinct regions including strainable networks inaccordance with one or more implementations of the present invention;

FIG. 12A illustrates a schematic diagram of an implementation ofembossing intermeshing rollers for use in accordance with one or moreimplementations of the present invention;

FIG. 12B illustrates a close up of the protrusions and intermeshingrecessions of the rollers of FIG. 12A;

FIG. 12C illustrates a view of a multi-layered thermoplastic film withvisually-distinct regions created by the intermeshing rollers of FIG.12A;

FIG. 13 illustrates a bag incorporating the multi-layered film withvisually-distinct regions of FIG. 4 and visually-distinct side seals inaccordance with one or more implementations of the present invention;

FIG. 14 illustrates a bag incorporating a multi-layered film withvisually-distinct regions and decorative visually-distinct side seals inaccordance with one or more implementations of the present invention;

FIG. 15 illustrates another bag having visually-distinct seals inaccordance with one or more implementations of the present invention;

FIG. 16 illustrates a bag incorporating sections of different patternsof visually-distinct regions and visually-distinct seals in accordancewith one or more implementations of the present invention;

FIG. 17 illustrates a schematic diagram of a bag manufacturing processin accordance with one or more implementations of the present invention;

FIG. 18A illustrates a sealing process in accordance with one or moreimplementations of the present invention;

FIG. 18B illustrates a seal bar in accordance with one or moreimplementations of the present invention;

FIG. 18C illustrates another seal bar in accordance with one or moreimplementations of the present invention;

FIG. 19 illustrates another sealing process in accordance with one ormore implementations of the present invention;

FIG. 20 illustrates a schematic diagram of another bag manufacturingprocess in accordance with one or more implementations of the presentinvention;

FIG. 21 illustrates a schematic diagram of yet another bag manufacturingprocess in accordance with one or more implementations of the presentinvention; and

FIG. 22 illustrates a schematic diagram of still another bagmanufacturing process in accordance with one or more implementations ofthe present invention.

DETAILED DESCRIPTION

One or more implementations of the present invention include films andbags with a unique appearance and visually-distinct regions. Inparticular, the appearance of the films can provide multi-layers filmswith a unique metallic or other appearance that differs from theappearance of the individual layers alone. The films can benon-continuously bonded together and have regions in which the layersare in intimate contact. Such regions can be visually distinct from theother areas of the film in which the layers are not in intimate contact.The visually-distinct regions can provide a visual cue to the consumerabout the strength and quality of the film. Furthermore, thevisually-distinct regions can provide a unique and pleasing visualeffect.

In particular, one or more implementations include a multi-layer filmwith an outer layer that is substantially un-pigmented and incrementallystretched. The outer layer is non-continuously bonded to a pigmentedunder-lying layer such that the films are intermittingly in contact witheach other. One or more of the spacing between the films, the textureprovided by the incremental stretching of the outer layer, and thecombination of a substantially un-pigmented and an adjacent pigmentedlayer can provide the structure with an unexpected appearance thatdiffers from an appearance of the individual layers. For example, themulti-layer film can appear to be a color other than a color of thepigmented layer or the substantially un-pigmented layer (i.e., clear ortransparent layer). More specifically, in one example, the multi-layerfilm can have a metallic appearance. The multi-layer film can have themetallic look despite the lack of any metallic pigment.

One or more implementations can further include bringing portions of thesubstantially un-pigmented outer layer into intimate or direct contactwith the pigmented under layer. Bringing the under and outer layers intodirect contact can cause an appearance or color change to the areas orregions in intimate contact. In particular, the areas of intimatecontact can lose the unique appearance and instead have the color of thepigmented under-layer. Thus, one or more implementations involvecreating visually-distinct regions by bringing the outer and underlayers into intimate contact.

One will appreciate in light of the disclosure here that the under andouter layers of the multi-layer film with the unexpected appearance canbe brought into intimate contact with each other using various differenttechniques. In particular, one or more implementations involveheat-sealing the layers of the multi-layer film with the unexpectedappearance together. The heat-seals can create intimate contact betweenthe outer substantially un-pigmented layer and the under-layingpigmented layer causing the heat sealed area to take on the visualcharacteristics of the underlying pigmented film layer. Thus, ratherthan having the unexpected appearance (for example, a metallicappearance), the heat-sealed areas can appear the color of the pigmentedinner layer.

In order to emphasize such visually-distinct areas, one or moreembodiments can involve forming wide heat seals. Wide heat seals cancomprise heat seals with a width of at least 1/16th of an inch. Theincreased width of the heat seals can increase the size, and thus, thevisual effects of the visually-distinct heat seals.

Additionally or alternatively, one or more implementations can involvebringing the outer and under-lying layers of the multi-layer film withthe unexpected appearance into intimate contact with each other via ringrolling, a structural elastic like film (SELF) process, embossing, orother methods. One will appreciate in light of the disclosure hereinthat a manufacturer can provide a film or a bag with any number ofpatterns of visually-distinct regions. Consumers can associate thevisually-distinct regions with improved properties or strength. Forexample, the visually-distinct regions can indicate that those regionshave undergone a transformation to impart a desirable characteristic tothat region (e.g., increased strength). Thus, the visually-distinctregions can serve to notify a consumer that the multi-layeredthermoplastic film has been processed to improve the film.

In one or more implementations the combined layers of the multi-layeredbag may use less material than a conventional bag, but nonetheless havemaintained or increased strength parameters provided by the layers ofthe bag working in concert with each other. In particular, in one ormore implementations the layers of the multi-layered bag are thinnerand/or stretched to reduce the amount of thermoplastic material to forma bag of a given size. For instance, one or more layers of themulti-layered bag can be continuously stretched or incrementallystretched to thin the layer and/or increase or otherwise modify thestrength parameters of the layers.

In addition to allowing the creation of visually-distinct regions,discontinuous bonding can also enhance the strength and other propertiesof the film. In particular, one or more implementations provide forforming bonds between adjacent layers of a multi-layer film that arerelatively light such that forces acting on the multi-layer film arefirst absorbed by breaking the bonds rather than or prior to tearing orotherwise causing the failure of the layers of the multi-layer film.Such implementations can provide an overall thinner film employing areduced amount of raw material that nonetheless has maintained orincreased strength parameters. Alternatively, such implementations canuse a given amount of raw material and provide a film with increasedstrength parameters.

In particular, the light bonds or bond regions of adjacent layers ofmulti-layer films in accordance with one or more implementations can actto first absorb forces via breaking of the bonds prior to allowing thatsame force to cause failure of the individual layers of the multi-layerfilm. Such action can provide increased strength to the multi-layerfilm. In one or more implementations, the light bonds or bond regionsinclude a bond strength that is advantageously less than a weakest tearresistance of each of the individual films so as to cause the bonds tofail prior to failing of the film layers. Indeed, one or moreimplementations include bonds that the release just prior to anylocalized tearing of the layers of the multi-layer film.

Thus, in one or more implementations, the light bonds or bond regions ofa multi-layer film can fail before either of the individual layersundergoes molecular-level deformation. For example, an applied straincan pull the light bonds or bond regions apart prior to anymolecular-level deformation (stretching, tearing, puncturing, etc.) ofthe individual film layers. In other words, the light bonds or bondregions can provide less resistive force to an applied strain thanmolecular-level deformation of any of the layers of the multi-layerfilm. The inventors have surprisingly found that such a configuration oflight bonding can provide increased strength properties to themulti-layer film as compared to a monolayer film of equal thickness or amulti-layer film in which the plurality of layers are tightly bondedtogether (e.g., coextruded).

One or more implementations of the present invention provide fortailoring the bonds or bond regions between layers of a multi-layer filmto ensure light bonding and associated increased strength. For example,one or more implementations include modifying or tailoring one or moreof a bond strength, bond density, bond pattern, or bond size betweenadjacent layers of a multi-layer film to deliver a film with strengthcharacteristics better than or equal to the sum of the strengthcharacteristics of the individual layers. Such bond tailoring can allowfor multi-layer films at a lower basis weight (amount of raw material)to perform the same as or better than higher basis weight mono-layer orco-extruded films.

Relatively weak bonding and stretching of the two or more layers of themulti-layer film can be accomplished simultaneously through one or moresuitable techniques. For example, bonding and stretching may be achievedby pressure (for example MD ring rolling, TD ring rolling, DD ringrolling, stainable network lamination, or embossing), or with acombination of heat and pressure. Alternately, a manufacturer can firststretch the films and then bond the films using one or more bondingtechniques. For example, one or more implementations can includeultrasonic bonding to lightly laminate the film layers. Alternately oradditionally, adhesives can laminate the films. Treatment with a Coronadischarge can enhance any of the above methods. Prior to lamination, theseparate layers can be flat film or can be subject to separateprocesses, such as stretching, slitting, coating and printing, andcorona treatment.

As used herein, the terms “lamination,” “laminate,” and “laminatedfilm,” refer to the process and resulting product made by bondingtogether two or more layers of film or other material. The term“bonding”, when used in reference to bonding of multiple layers of amulti-layer film, may be used interchangeably with “lamination” of thelayers. According to methods of the present invention, adjacent layersof a multi-layer film are laminated or bonded to one another. Thebonding purposely results in a relatively weak bond between the layersthat has a bond strength that is less than the strength of the weakestlayer of the film. This allows the lamination bonds to fail before thefilm layer, and thus the film, fails.

The term laminate is also inclusive of coextruded multilayer filmscomprising one or more tie layers. As a verb, “laminate” means to affixor adhere (by means of, for example, adhesive bonding, pressure bonding,ultrasonic bonding, corona lamination, and the like) two or moreseparately made film articles to one another so as to form a multi-layerstructure. As a noun, “laminate” means a product produced by theaffixing or adhering just described.

In one or more implementations, the light lamination or bonding betweenlayers of a multi-layer film may be non-continuous (i.e., discontinuousor partial discontinuous). As used herein the terms “discontinuousbonding” or “discontinuous lamination” refers to lamination of two ormore layers where the lamination is not continuous in the machinedirection and not continuous in the transverse direction. Moreparticularly, discontinuous lamination refers to lamination of two ormore layers with repeating bonded patterns broken up by repeatingun-bonded areas in both the machine direction and the transversedirection of the film.

As used herein the terms “partially discontinuous bonding” or “partiallydiscontinuous lamination” refers to lamination of two or more layerswhere the lamination is substantially continuous in the machinedirection or in the transverse direction, but not continuous in theother of the machine direction or the transverse direction. Alternately,partially discontinuous lamination refers to lamination of two or morelayers where the lamination is substantially continuous in the width ofthe article but not continuous in the height of the article, orsubstantially continuous in the height of the article but not continuousin the width of the article. More particularly, partially discontinuouslamination refers to lamination of two or more layers with repeatingbonded patterns broken up by repeating unbounded areas in either themachine direction or the transverse direction.

As used herein, the term “substantially un-pigmented” refers to athermoplastic ply or plies that are substantially free of a significantamount of pigment such that the ply is substantially transparent ortranslucent. For example, a “substantially un-pigmented” film can have apigment concentration (i.e., percent of total composition of the film)that is between 0% and 2%. In some embodiments, a “substantiallyun-pigmented” film can have a pigment concentration between about 0% andabout 1%. In further embodiments, a “substantially un-pigmented” filmcan have a pigment concentration between about 0% and about 0.75%. Asused herein, the term “pigmented” refers to a thermoplastic ply or pliesthat are pigmented such that the ply has a pigment concentration over 3%or is otherwise substantially opaque.

As used herein, the term “pigment or pigments” are solids of an organicand inorganic nature which are defined as such when they are used withina system and incorporated into the thermoplastic, absorbing part of thelight and reflecting the complementary part thereof which forms thecolor of the thermoplastic ply. Representative, but not limiting,examples of suitable pigments include inorganic colored pigments such assuch as iron oxide, in all their shades of yellow, brown, red and black;and in all their physical forms and particle-size categories, chromiumoxide pigments, also co-precipitated with nickel and nickel titanates,blue and green pigments derived from copper phthalocyanine, alsochlorinated and brominated in the various alpha, beta and epsiloncrystalline forms, yellow pigments derived from lead sulphochromate,yellow pigments derived from lead bismuth vanadate, orange pigmentsderived from lead sulphochromate molybdate lead oxide, cadmium sulfide,cadmium selenide, lead chromate, zinc chromate, nickel titanate, and thelike. For the purposes of the present invention, the term “organicpigment” comprises also black pigments resulting from organic combustion(so-called “carbon black”). Organic colored pigments include yellowpigments of an organic nature based on arylamides, orange pigments of anorganic nature based on naphthol, orange pigments of an organic naturebased on diketo-pyrrolo-pyrole, red pigments based on manganese salts ofazo dyes, red pigments based on manganese salts of beta-oxynaphthoicacid, red organic quinacridone pigments, and red organic anthraquinonepigments. Organic colored pigments include azo and diazo pigments,phthalocyanines, quinacridone pigments, perylene pigments,isoindolinone, anthraquinones, thioindigo, solvent dyes and the like.

Pigments can be light reflecting (e.g., white pigments) or lightabsorbing (e.g., black pigments). Examples of pigments suitable for oneor more implementations include titanium dioxide, Antimony Oxide, ZincOxide, Carbonate, White Lead, Lithopone, Clay, Magnesium Silicate,Barytes (BaSO4), and Calcium Carbonate (CaCO3)

Film Materials

As an initial matter, the thermoplastic material of the films of one ormore implementations can include, but are not limited to, thermoplasticpolyolefins, including polyethylene and copolymers thereof andpolypropylene and copolymers thereof. The olefin based polymers caninclude the most common ethylene or propylene based polymers such aspolyethylene, polypropylene, and copolymers such as ethylenevinylacetate (EVA), ethylene methyl acrylate (EMA) and ethylene acrylicacid (EAA), or blends of such polyolefins.

Other examples of polymers suitable for use as films in accordance withthe present invention include elastomeric polymers. Suitable elastomericpolymers may also be biodegradable or environmentally degradable.Suitable elastomeric polymers for the film includepoly(ethylene-butene), poly(ethylene-hexene), poly(ethylene-octene),poly(ethylene-propylene), poly(styrene-butadiene-styrene),poly(styrene-isoprene-styrene), poly(styrene-ethylene-butylene-styrene),poly(ester-ether), poly(ether-amide), poly(ethylene-vinylacetate),poly(ethylene-methylacrylate), poly(ethylene-acrylic acid),poly(ethylene butylacrylate), polyurethane,poly(ethylene-propylene-diene), ethylene-propylene rubber.

The examples and description herein below refer to films formed fromlinear low-density polyethylene. The term “linear low-densitypolyethylene” (LLDPE) as used herein is defined to mean a copolymer ofethylene and a minor amount of an olefin containing 4 to 10 carbonatoms, having a density of from about 0.910 to about 0.926, and a meltindex (MI) of from about 0.5 to about 10. For example, some examplesherein use an octene comonomer, solution phase LLDPE (MI=1.1; ρ=0.920).Additionally, other examples use a gas phase LLDPE, which is a hexenegas phase LLDPE formulated with slip/AB (MI=1.0; ρ=0.920). Still furtherexamples use a gas phase LLDPE, which is a hexene gas phase LLDPEformulated with slip/AB (MI=1.0; ρ=0.926). One will appreciate that thepresent invention is not limited to LLDPE, and can include “high densitypolyethylene” (HDPE), “low density polyethylene” (LDPE), and “very lowdensity polyethylene” (VLDPE). Indeed films made from any of thepreviously mentioned thermoplastic materials or combinations thereof canbe suitable for use with the present invention.

Indeed, implementations of the present invention can include anyflexible or pliable thermoplastic material that may be formed or drawninto a web or film. Furthermore, the thermoplastic materials may includea single layer or multiple layers. The thermoplastic material may beopaque, transparent, translucent, or tinted. Furthermore, thethermoplastic material may be gas permeable or impermeable.

As used herein, the term “flexible” refers to materials that are capableof being flexed or bent, especially repeatedly, such that they arepliant and yieldable in response to externally applied forces.Accordingly, “flexible” is substantially opposite in meaning to theterms inflexible, rigid, or unyielding. Materials and structures thatare flexible, therefore, may be altered in shape and structure toaccommodate external forces and to conform to the shape of objectsbrought into contact with them without losing their integrity. Inaccordance with further prior art materials, web materials are providedwhich exhibit an “elastic-like” behavior in the direction of appliedstrain without the use of added traditional elastic. As used herein, theterm “elastic-like” describes the behavior of web materials which whensubjected to an applied strain, the web materials extend in thedirection of applied strain, and when the applied strain is released theweb materials return, to a degree, to their pre-strained condition.

In addition to a thermoplastic material, films of one or moreimplementations of the present invention can also include one or moreadditives. Additional additives that may be included in one or moreembodiments include slip agents, anti-block agents, voiding agents, ortackifiers. Additionally, one or more implementations of the presentinvention include films that are devoid of voiding agents. Some examplesof voiding agents include calcium carbonate, magnesium carbonate, bariumcarbonate, calcium sulfate, magnesium sulfate, barium sulfate, calciumoxide, magnesium oxide, titanium oxide, zinc oxide, aluminum hydroxide,magnesium hydroxide, talc, clay, silica, alumina, mica, glass powder,starch, etc.

One will appreciate in light of the disclosure herein that manufacturersmay form the films or webs to be used with one or more implementationsof the present invention using a wide variety of techniques. Forexample, a manufacturer can form precursor mix of the thermoplasticmaterial and one or more additives. The manufacturer can then form thefilm(s) from the precursor mix using conventional flat or cast extrusionor coextrusion to produce monolayer, bilayer, or multilayer films.Alternatively, a manufacturer can form the films using suitableprocesses, such as, a blown film process to produce monolayer, bilayer,or multilayer films. If desired for a given end use, the manufacturercan orient the films by trapped bubble, tenterframe, or other suitableprocess. Additionally, the manufacturer can optionally anneal the filmsthereafter.

An optional part of the film-making process is a procedure known as“orientation.” The orientation of a polymer is a reference to itsmolecular organization, i.e., the orientation of molecules relative toeach other. Similarly, the process of orientation is the process bywhich directionality (orientation) is imposed upon the polymericarrangements in the film. The process of orientation is employed toimpart desirable properties to films, including making cast filmstougher (higher tensile properties). Depending on whether the film ismade by casting as a flat film or by blowing as a tubular film, theorientation process can require different procedures. This is related tothe different physical characteristics possessed by films made by thetwo conventional film-making processes; casting and blowing. Generally,blown films tend to have greater stiffness and toughness. By contrast,cast films usually have the advantages of greater film clarity anduniformity of thickness and flatness, generally permitting use of awider range of polymers and producing a higher quality film.

When a film has been stretched in a single direction (monoaxialorientation), the resulting film can exhibit strength and stiffnessalong the direction of stretch, but can be weak in the other direction,i.e., across the stretch, often splitting when flexed or pulled. Toovercome this limitation, two-way or biaxial orientation can be employedto more evenly distribute the strength qualities of the film in twodirections. Most biaxial orientation processes use apparatus thatstretches the film sequentially, first in one direction and then in theother.

In one or more implementations, one or more films of the presentinvention are blown film, or cast film. Blown film and cast film isformed by extrusion. The extruder used can be a conventional one using adie, which will provide the desired gauge. Some useful extruders aredescribed in U.S. Pat. Nos. 4,814,135; 4,857,600; 5,076,988; 5,153,382;each of which are incorporated herein by reference in their entirety.Examples of various extruders, which can be used in producing the filmsto be used with the present invention, can be a single screw typemodified with a blown film die, an air ring, and continuous take offequipment.

In one or more implementations, a manufacturer can use multipleextruders to supply different melt streams, which a feed block can orderinto different channels of a multi-channel die. The multiple extruderscan allow a manufacturer to form a multi-layered film with layers havingdifferent compositions. Such multi-layer film may later benon-continuously laminated with another layer of film to provide one ormore benefits of the present invention.

In a blown film process, the die can be an upright cylinder with acircular opening. Rollers can pull molten plastic upward away from thedie. An air-ring can cool the film as the film travels upwards. An airoutlet can force compressed air into the center of the extruded circularprofile, creating a bubble. The air can expand the extruded circularcross section by a multiple of the die diameter. This ratio is calledthe “blow-up ratio.” When using a blown film process, the manufacturercan collapse the film to double the plies of the film. Alternatively,the manufacturer can cut and fold the film, or cut and leave the filmunfolded.

In any event, in one or more embodiments, the extrusion process canorient the polymer chains of the blown film. The “orientation” of apolymer is a reference to its molecular organization, i.e., theorientation of molecules or polymer chains relative to each other. Inparticular, the extrusion process can cause the polymer chains of theblown film to be predominantly oriented in the machine direction. Asused herein predominately oriented in a particular direction means thatthe polymer chains are more oriented in the particular direction thananother direction. One will appreciate, however, that a film that ispredominately oriented in a particular direction can still includepolymer chains oriented in directions other than the particulardirection. Thus, in one or more embodiments the initial or startingfilms (films before being stretched or bonded or laminated in accordancewith the principles described herein) can comprise a blown film that ispredominately oriented in the machine direction.

The process of blowing up the tubular stock or bubble can further orientthe polymer chains of the blown film. In particular, the blow-up processcan cause the polymer chains of the blown film to be bi-axiallyoriented. Despite being bi-axially oriented, in one or more embodimentsthe polymer chains of the blown film are predominantly oriented in themachine direction (i.e., oriented more in the machine direction than thetransverse direction).

The films of one or more implementations of the present invention canhave a starting gauge between about 0.1 mils to about 20 mils, suitablyfrom about 0.2 mils to about 4 mils, suitably in the range of about 0.3mils to about 2 mils, suitably from about 0.6 mils to about 1.25 mils,suitably from about 0.9 mils to about 1.1 mils, suitably from about 0.3mils to about 0.7 mils, and suitably from about 0.4 mils and about 0.6mils. Additionally, the starting gauge of films of one or moreimplementations of the present invention may not be uniform. Thus, thestarting gauge of films of one or more implementations of the presentinvention may vary along the length and/or width of the film.

As an initial matter, one or more layers of the films described hereincan comprise any flexible or pliable material comprising a thermoplasticmaterial and that can be formed or drawn into a web or film. Asdescribed above, the film includes a plurality of layers ofthermoplastic films. Each individual film layer may itself include asingle layer or multiple layers. In other words, the individual layersof the multi-layer film may each themselves comprise a plurality oflaminated layers. Such layers may be significantly more tightly bondedtogether than the bonding provided by the purposely weak discontinuousbonding in the finished multi-layer film. Both tight and relatively weaklamination can be accomplished by joining layers by mechanical pressure,joining layers with adhesives, joining with heat and pressure, spreadcoating, extrusion coating, and combinations thereof. Adjacentsub-layers of an individual layer may be coextruded. Coextrusion resultsin tight bonding so that the bond strength is greater than the tearresistance of the resulting laminate (i.e., rather than allowingadjacent layers to be peeled apart through breakage of the laminationbonds, the film will tear).

FIG. 1A illustrates a film ply 10 a of a single layer 11. In anotherimplementation, as illustrated by FIG. 1B, a film ply 10 b can have twolayers (i.e., a bi-layered film). In particular, the film ply 10 b caninclude a first layer 11 a and a second layer 11 b. The first and secondlayers 11 a, 11 b can optionally include different grades ofthermoplastic material or include different additives, including polymeradditives. In still another implementation, shown in FIG. 1C, a film ply10 c can include three layers (i.e., a tri-layered film). For example,FIG. 1C illustrates that the film 10 c can include a first layer 11 c, asecond layer 11 d, and a third layer 11 e.

In one example, the film 10 a can comprise a 0.5 mil, 0.920 densityLLDPE, black film containing 4.8% carbon black. In an alternativeembodiment, the film 10 a can comprise a 0.5 mil, 0.920 density LLDPE,un-pigmented film that appears clear or substantially clear.

In at least one implementation, such as shown in FIG. 1C, a multilayeredfilm 10 c can include co-extruded layers. For example, the film 10 c caninclude a three-layer B:A:B structure, where the ratio of layers can be20:60:20. The exterior B layers (i.e., 11 c, 11 e) can comprise amixture of hexene LLDPE of density 0.918, and metallocene LLDPE ofdensity 0.918. The interior A core layer (11 d) can comprise a mixtureof hexene LLDPE of density 0.918, butene LLDPE of density 0.918,reclaimed resin from trash bags. Additionally, the A core layer 11 d caninclude a pigment. For example, the A core layer 11 d can include acolorant containing carbon black in an amount between about 0.1 percentand about 6%.

In another example, the film 10 c is a coextruded three-layer B:A:Bstructure where the ratio of layers is 15:70:15. The A core layer 11 dcan comprise a LLDPE material, and the B outer layers 11 c, 11 e caninclude added C6 olefin LLDPE. The LLDPE material can have a MI of 1.0and density of 0.920 g/cm3. The B:A:B structure can also optionally havea ratio of B:A that is greater than 20:60 or less than 15:70. In one ormore implementations, the LLDPE can comprise greater than 50% of theoverall thermoplastic material in the film 10 c.

In another example, the film 10 c is a coextruded three-layer C:A:Bstructure where the ratio of layers is 20:60:20. The C layer 11 c cancomprise a LLDPE material with a first colorant (e.g., black). The Blayer 11 e can also comprise a LLDPE material with a second colorant(e.g., white). The LLDPE material can have a MI of 1.0 and density of0.920 g/cm3. The A core layer 11 d can comprise similar materials to anyof the core layer describe above. The A core layer 11 d can comprise ablack colorant or can be clear.

In any event, one or more implementations involve forming a multi-layerfilm with a metallic or color that is distinct from the color andappearance of the individual layers of the multi-layer film. Forexample, a pigmented under layer can have a black appearance while theouter layer has a clear or transparent appearance. When combined to forma multi-layer film in accordance the principles described herein, theresultant multi-layer film can have a metallic, silvery or grey colorrather than a black appearance or color as would be expected. Once sucha multi-layer film with a unique appearance is formed, one or moreimplementations of the present invention involve bringing regions orareas of the two layers into intimate contact with each other to createvisually-distinct regions that have the color or appearance of thepigmented layer. For example, a multi-layer film with a black inner orunder layer and a transparent outer layer can have a silver metallicappearance and black visually-distinct regions where the two films arein intimate contact with each other.

One will appreciate in light of the disclosure herein that the methodsof bringing the layers of the multi-layer film together to formvisually-distinct areas can be performed as part of the process offorming the multi-layer film or as additional acts. For example, theprocess of discontinuously bonding the layers of a pigmented and anadjacent un-pigmented layer can act to both form the multi-layer filmwith a unique appearance and simultaneously create visually-distinctregions. In particular, a ring rolling, SELFing, embossing, or otherdiscontinuous bonding process can both bond the pigmented and adjacentun-pigmented layer together and create visually-distinct regions.

Alternatively, once a multi-layer film with a unique appearance iscreated, additional processing steps can be performed to form thevisually-distinct regions. For example, a manufacturer can perform aring rolling, SELFing, embossing, heat sealing, or other process on amulti-layer film with a unique appearance to create visually-distinctareas that have the color or appearance of the pigmented layer. One willappreciate in light of the disclosure herein that one or moreimplementations of the present invention can involve any number ofvariations or combinations of acts and processes to form a multi-layerfilm with a unique appearance and visually-distinct areas or regions.

In any event, a multi-layer film with a unique appearance can comprise afilm with an un-pigmented and incrementally-stretched outer layer thatis discontinuously bonded to a pigmented under layer. For example, FIG.2 illustrates one example of a multi-layer film 13 with uniqueappearance (e.g., metallic appearance). The multi-layer film 13 includesan outer layer 10 and an inner or under layer 10′. Each of the layerscan comprise any of the films 10 a-10 c described above or a film withmore than three layers.

In any event, the outer layer 10 can be un-pigmented such that the filmis clear or transparent. The outer layer 10 can further be incrementallystretched. For example, FIG. 2 illustrates that the outer layer 10includes alternating series of stretched (or more stretched) regions orthinner webs 46 adjacent to un-stretched regions (or less stretched) orthicker ribs 44. As explained in greater detail below, the manufacturercan incrementally stretch the outer layer 10 using one or more of ringrolling or SELFing.

FIG. 2 further illustrates that the outer layer 10 of the multi-layerfilm 13 is discontinuously bonded to the inner layer 10′. In particular,the multi-layer film 13 can include bonded regions or bonds 49 andun-bonded regions 47. For example, FIG. 2 illustrates that the filmlayers 10, 10′ of the multi-layer film 13 are laminated together at thethicker ribs 44 while the stretched (i.e., thinner) regions 46 may notbe laminated together. In particular, a gap 47 or un-bonded region canseparate the film layers 10, 10′.

As explained previously, the configuration of the multi-layer film 13can provide the multi-layer film 13 with a metallic, gray, silvery, orother unexpected appearance when viewing the outer layer 10. Theunexpected appearance is un-expected typically viewing a pigmented filmthrough a clear or transparent film would appear as the color of thepigment rather than having a different color or appearance.

As shown by FIG. 2, the bonded regions 49 can comprise areas in whichthe outer layer 10′ is in direct or intimate contact with the innerlayer 10′. As such, the bonded regions 49 can be visually distinct fromthe rest of the multi-layer film. In other words, because the clear ortransparent film 10 is directly abutted against the pigmented film 10′,the bonded regions can have the color or appearance of the pigmentedfilm 10′. Thus, when the pigmented film 10′ is a black film, the bondedregions 49 can appear black with the unbounded regions 47 (i.e., thethinner webs 46 and transitions between the bonds 49 and the thinnerwebs) can appear metallic, grey, or another unexpected appearance.

FIG. 2 illustrates that the bonded regions 49 are aligned with andco-extensive with the thinner ribs 44. One will appreciate in light ofthe disclosure herein that the present invention is not so limited. Forexample, in alternative embodiments the bonds or bonded regions 49 arealigned with but not co-extensive with the thicker ribs 44. In stillfurther embodiments, the bonds or bonded regions 49 may cross orotherwise interface with the thicker ribs 44 but may not be aligned withor co-expensive with the thicker ribs. In yet further embodiments, thebonds or bonded regions 49 may not interface with the thicker ribs 44.

As previously mentioned, according to one implementation of theinvention, the separate layers are non-continuously bonded to oneanother and incrementally stretched to form a multi-layer film 13 asdescribed above in relation to FIG. 2. FIGS. 3A-3B illustrate exemplaryprocesses of partially discontinuously bonding adjacent layers 15 inaccordance with an implementation of the present invention to create amulti-layer film 13. In particular, FIGS. 3A-3B illustrate an MD ringrolling process that partially discontinuously laminates individualadjacent layers 15 by passing the layers through a pair of MDintermeshing rollers 12, 14. As a result of MD ring rolling, themulti-layered film 13 is also intermittently stretched in the machinedirection MD.

As shown by the FIGS. 3A-3B, the first roller 12 and the second roller14 can each have a generally cylindrical shape. The MD intermeshingrollers 12, 14 may be made of cast and/or machined metal, such as,steel, aluminum, or any other suitable material. The MD intermeshingrollers 12, 14 can rotate in opposite directions about parallel axes ofrotation. For example, FIG. 3A illustrates that the first roller 12 canrotate about a first axis 16 of rotation in a counterclockwise direction18. FIG. 3A also illustrates that the second roller 14 can rotate abouta second axis 20 of rotation in a clockwise direction 22. The axes ofrotation 16, 20 can be parallel to the transverse direction TD andperpendicular to the machine direction MD.

The intermeshing rollers 12, 14 can closely resemble fine pitch spurgears. In particular, the MD intermeshing rollers 12, 14 can include aplurality of protruding ridges 24, 26. The ridges 24, 26 can extendalong the MD intermeshing rollers 12, 14 in a direction generallyparallel to axes of rotation 16, 20 and perpendicular to the machinedirection of the film 13 passing through the MD intermeshing rollers 12,14. Furthermore, the ridges 24, 26 can extend generally radially outwardfrom the axes of rotation 16, 20. The tips of ridges 24, 26 can have avariety of different shapes and configurations. For example, the tips ofthe ridges 24, 26 can have a rounded shape as shown in FIG. 3B. Inalternative implementations, the tips of the ridges 24, 26 can havesharp angled corners. FIGS. 3A-3B also illustrate that grooves 28, 30can separate adjacent ridges 24, 26.

The ridges 24 on the first roller 12 can be offset or staggered withrespect to the ridges 26 on the second roller 14. Thus, the grooves 28of the first roller 12 can receive the ridges 26 of the second roller14, as the MD intermeshing rollers 12, 14 intermesh. Similarly, thegrooves 30 of the second roller 14 can receive the ridges 24 of thefirst roller 12.

One will appreciate in light of the disclosure herein that theconfiguration of the ridges 24, 26 and grooves 28, 30 can preventcontact between ridges 24, 26 during intermeshing so that no rotationaltorque is transmitted during operation. Additionally, the configurationof the ridges 24, 26 and grooves 28, 30 can affect the amount ofstretching and the bond strength resulting from partially discontinuouslamination as the film layers 15 pass through MD intermeshing rollers12, 14.

Referring specifically to FIG. 3B, various features of the ridges 24, 26and grooves 28, 30 are shown in greater detail. The pitch and depth ofengagement of the ridges 24, 26 can determine, at least in part, theamount of incremental stretching and partially discontinuous laminationcaused by the MD intermeshing rollers 12, 14. As shown by FIG. 3B, thepitch 32 is the distance between the tips of two adjacent ridges on thesame roller. The “depth of engagement” (“DOE”) 34 is the amount ofoverlap between ridges 24, 26 of the different MD intermeshing rollers12, 14 during intermeshing.

The ratio of DOE 34 to pitch 32 can determine, at least in part, thebond strength provided by the partially discontinuous bonding. Accordingto one embodiment, the ratio of DOE to pitch provided by any ringrolling operation is less than about 1.1:1, suitably less than about1.0:1, suitably between about 0.5:1 and about 1.0:1, or suitably betweenabout 0.8:1 and about 0.9:1.

As shown by FIG. 3A, the direction of travel of the film layers 15through the MD intermeshing rollers 12, 14 is parallel to the machinedirection and perpendicular to the transverse direction. As thethermoplastic film layers 15 pass between the MD intermeshing rollers12, 14, the ridges 24, 26 can incrementally stretch the film layers 15in the machine direction. In one or more implementations, stretching thefilm layers 15 in the machine direction can reduce the gauge of the filmand increase the length of the film layers 15. In other implementations,the film layers 15 may rebound after stretching such that the gauge ofthe film layers 15 are not decreased. Furthermore, in one or moreimplementations, stretching the film layers 15 in the machine directioncan reduce the width of the film layers 15. For example, as film layers15 are lengthened in the machine direction, the length of the filmlayers 15 can be reduced in the transverse direction.

In particular, as the film layers 15 proceed between the MD intermeshingrollers 12, 14, the ridges 24 of the first roller 12 can push the filmlayers 15 into the grooves 30 of the second roller 14 and vice versa.The pulling of the film layers 15 by the ridges 24, 26 can stretch thefilm layers 15. The MD intermeshing rollers 12, 14 may not stretch thefilm layers 15 evenly along their length. Specifically, the MDintermeshing rollers 12, 14 can stretch the portions of the film layers15 between the ridges 24, 26 more than the portions of the film layers15 that contact the ridges 24, 26. Thus, the MD intermeshing rollers 12,14 can impart or form a generally striped pattern 36 into the filmlayers 15. As used herein, the terms “impart” and “form” refer to thecreation of a desired structure or geometry in a film upon stretchingthe film that will at least partially retain the desired structure orgeometry when the film is no longer subject to any strains or externallyapplied forces.

FIGS. 3A-3B illustrate that the film layers 15 (i.e., the films that areyet to pass through the MD intermeshing rollers 12, 14) can have asubstantially flat top surface 38 and substantially flat bottom surface40. As seen in FIG. 3B, the multi-layer film 13 may comprise two layers10 and 10′ that are initially separate from one another. The film layers15 can have an initial thickness or starting gauge 42 (i.e., the sum of42 a and 42 b) extending between its major surfaces (i.e., the topsurface 38 and the bottom surface 40). In at least one implementation,the starting gauge 42, as well as the gauge 42 a, 42 b of individuallayers 10 and 10′ can be substantially uniform along the length of thefilm layers 15. Because the inner surfaces of each layer 10 and 10′ aresomewhat tacky, the layers become lightly bonded together as they arepulled through and stretched by MD intermeshing rollers 12, 14. Thoseareas that are un-stretched or stretched less become bonded together.

In one or more implementations, the film layers 15 need not have anentirely flat top surface 38, but may be rough or uneven. Similarly,bottom surface 40 or the inner oriented surfaces of layers 10 and 10′ ofthe film layers 15 can also be rough or uneven. Further, the startinggauge 42, 42 a, and 42 b need not be consistent or uniform throughoutthe entirety of film layers 15. Thus, the starting gauge 42, 42 a, and42 b can vary due to product design, manufacturing defects, tolerances,or other processing issues. According to one embodiment, one or more ofthe individual layers 10 and 10 c′ may be pre-stretched (e.g., throughMD ring rolling, TD ring rolling, etc.) before being positioned adjacentto the other layer (10′ or 10, respectively). Such pre-stretching ofindividual layers can result in a striped surface exhibiting an uneventop and bottom surface similar to that seen in FIG. 3A.

FIG. 3B illustrates that film layers 15, can include two initiallyseparate film layers 10, 10′. In an alternative implementation, the filmlayers 15 (and thus the resultant multi-layer film 13) can include threeinitially separate film layers: a middle film layer and two outer filmlayers. In other embodiments, more than three layers may be provided(four, five, six, or more partially discontinuously or discontinuouslylaminated layers).

As seen in FIG. 3A, upon stretching and partially discontinuouslylaminating the adjacent layers 15, the intermittingly bonded andstretched multi-layer film 13 can include a striped pattern 36. Thestriped pattern 36 can include alternating series of stretched (or morestretched) regions or thinner webs 46 adjacent to un-stretched regions(or less stretched) or thinner ribs 44. FIG. 3B illustrates that the MDintermeshing rollers 12, 14 can incrementally stretch and partiallydiscontinuously bond films 10, 10′ to create the multi-layer film 13including bonded regions or bonds 49 and un-bonded regions 47. Forexample, FIG. 3B illustrates that the film layers 10, 10′ of themulti-layer film 13 can be laminated together at the thicker ribs 44while the stretched (i.e., thinner) regions 46 may not be laminatedtogether.

In addition to any compositional differences between layers 10, 10′ of agiven multi-layer film, the different film layers can have differinggauges or thicknesses. In one or more implementations, the film layersmay be substantially equal to one another in thickness. For example, theinventors have found that the MD or TD tear resistance of the composite,multi-layer film is typically approximately equal to the lowest MD or TDtear value of the individual layers, absent any increase in tearresistance provided by light bonding. In other words, the weakest layeroften determines the strength of the multi-layer film structure.

As shown by FIG. 3B the bonded regions 49 of the multi-layer film 13 canhave an average thickness or gauge 50 a. The average gauge 50 a can beapproximately equal to the combined starting gauges 42 a, 42 b of thestarting films. In the Figures, separation between the layers atunbounded regions 47 is exaggerated for purposes of clarity. In one ormore implementations, the average gauge 50 a can be less than thecombined starting gauges 42 a-42 b. The films 10, 10′ of the un-bondedregions 47 can each have an average thickness or gauge 42 c, 42 d. Inone or more implementations, the average gauges 42 c, 42 d are less thanthe starting gauges 42 a, 42 b. Although the un-stretched regions orthicker ribs 44 of the multi-layered lightly-laminated films may bestretched to a small degree by MD intermeshing rollers 12,14 (orstretched in a separate operation), the un-stretched regions or thickerribs 44 may be stretched significantly less compared to the stretchedregions 46.

In any event, FIGS. 3A-3B illustrate that MD intermeshing rollers 12, 14can process the initially separately layered films 15 into MDincrementally-stretched multi-layer film 13. As previously mentioned,the MD incrementally-stretched multi-layer film 13 can include a stripedpattern 36 where the bonding occurs along a continuous line or regionalong the width of the film, parallel to the TD direction. The stripedpattern 36 can include alternating series of un-bonded regions 47 andbonded regions 49. The bonded regions 49 can comprise bonds betweenun-stretched regions or thicker ribs 44 of the films 10, 10′. In otherwords, the bonds of the MD incrementally-stretched multi-layer film 13can be positioned directly between, be aligned with, and bond togetherun-stretched regions or thicker ribs 44. Along related lines, theun-bonded regions 47 can separate the stretched or thinner regions 46.

FIG. 4 illustrates a top view of the MD incrementally-stretchedmulti-layer film 13. As shown by FIG. 4, the multi-layer film 13includes thicker ribs 44 bonded together to form bonded regions 49adjacent to thinner regions 46 that form un-bonded regions 47. Inaddition to resulting in partially discontinuous lamination of adjacentlayers, MD ring rolling the film layers 15 can increase or otherwisemodify one or more of the tensile strength, tear resistance, impactresistance, or elasticity of the film layers 15, in addition to whateveradditional strength is provided by the partially discontinuous, lowstrength bonds between adjacent layers of the film. Such bonds can bebroken to absorb forces rather than such forces resulting in tearing ofthe film.

Furthermore, thicker ribs 44 can include bonded stripes that extendacross the film 13 in a direction transverse (i.e., transversedirection) to a direction in which the film was extruded (i.e., machinedirection). As shown by FIG. 4, the bonded stripes or bonded regions 49can extend across the entire length of the film 13. One will appreciatein light of the disclosure herein that the striped pattern 36 may varydepending on the method used to incrementally stretch and partiallydiscontinuously bond adjacent layers 15. To the extent that MD or otherring rolling is used to lightly bond the film 13, the striped pattern 36(e.g., width and spacing of the stripes or stretched regions 44) on thefilm 13 can depend on the pitch 32 of the ridges 24, 26, the DOE 34, andother factors. As regions 49 represent areas of the multi-layer film inwhich the adjacent layers are bonded to one another, it will be apparentthat altering the spacing and/or width of regions 49 can affect theoverall strength of the film. For example, providing more bonded surfacearea relative to the unbonded surface area can increase the density ofsuch bonds that can absorb forces, increasing the film strength.

FIG. 4 further illustrates that the bonded regions 49 can beintermittently dispersed about un-bonded regions 47. In particular, eachbonded region 49 can reside between adjacent un-bonded regions 47. Alongrelated lines, each thicker rib 44 can be intermittently dispersed aboutstretched regions 46. The striped pattern 36 may vary depending on themethod used to lightly laminate the film 13. In one or moreimplementations, the molecular structure of the thermoplastic materialof the film multi-layered 13 may be rearranged during stretching (e.g.,particularly so during cold stretching).

One will appreciate in light of the disclosure herein that passing thefilm layers 15 through the MD intermeshing rollers 12, 14 to form themulti-layer film 13 can also modify the orientation of the film. Inparticular, MD stretching a predominately MD oriented film can furtherorient the stretched regions 46 in the machine direction. Thus, thestretched regions 46 can have an MD orientation that is greater than theMD orientation of the thicker ribs 44.

Additionally, the bonded regions 49 and thicker ribs 44 can be visuallydistinct from the un-bonded regions 47 and thinner regions 46 as aresult bring the inner and outer layers 10, 10′ in direct contact asdescribed above. One will appreciate that the size of the upper surfacesof the ridges 24, 26 can dictate the visibility of any visually-distinctregions created by the MD ring rolling. For example, in one or moreembodiments bonded regions 49 with a width less than 1/16th of an inchmay be somewhat difficult to detect or see. As such, in one or moreembodiments the upper surfaces of the ridges 24, 26 can have a widthequal to or greater than about 1/16th. In particular, in one or moreembodiments the upper surfaces of the ridges 24, 26 can have a width ofbetween about 1/16th of an inch and about 1 inch.

Referring to FIG. 4, the dotted areas/shaded areas of the multi-layerfilm 13 can have a metallic or other unexpected appearance, while thenon-dotted areas (in this case stripes) can have the appearance/color ofpigmented inner layer 10′. For example, when the pigmented film 10′ isblack, the dotted areas/shaded areas can have a silvery or grey metallicappearance while the non-dotted areas have a black appearance.

MD ring rolling is one exemplary method of partially discontinuouslylaminating a multi-layer film. TD ring rolling is another suitablemethod of discontinuously or partially discontinuously laminating afilm. For example, FIGS. 5A-5D illustrates a TD ring rolling processthat partially discontinuously and lightly bonds adjacent layers 15 bypassing the film layers 15 through a pair of TD intermeshing rollers 52,54. In particular, FIG. 5B illustrates thermoplastic films 15 prior topassing the film through the pair of TD intermeshing rollers 52, 54.FIG. 5C illustrates the thermoplastic films 15 as the films passesthrough the pair of TD intermeshing rollers 52, 54. FIG. 5D illustratesa resultant multi-layer film 13 a created from the thermoplastic films15 passing through the pair of TD intermeshing rollers 52, 54.

A TD ring rolling process (and associated TD intermeshing rollers 52,54) can be similar to the MD ring rolling process (and associated MDintermeshing rollers 12, 14) described herein above, except that theridges 56, 58 and grooves 60, 62 of the TD intermeshing rollers 52, 54extend generally orthogonally to the axes of rotation 16, 20 (i.e.,parallel to the MD direction). Thus, as shown by FIG. 5A, as thethermoplastic film layers 15 passes between the intermeshing rollers 52,54, the ridges 56, 58 can incrementally stretch and lightly bondadjacent layers 15. The resultant TD incrementally-stretched andincrementally-bonded multi-layer film 13 can include a striped pattern36 a within the with adjacent bonded and unbonded regions.

In particular, as the films 10, 10′ proceed between the TD intermeshingrollers 52, 54, the ridges 56 of the first roller 52 can push the films10, 10′ into the grooves 62 of the second roller 54 and vice versa. Thepulling of the films 10, 10′ by the ridges 56, 58 can stretch the films10, 10′. The rollers 52, 54 may not stretch the films 10, 10′ evenlyalong their length. Specifically, the rollers 52, 54 can stretch theportions of the films 10, 10′ between the ridges 56, 58 more than theportions of the films 10, 10′ that contact the ridges 56, 58, or viceversa. Thus, the rollers 52, 54 can impart or form a ribbed pattern 36 ainto resultant multi-layer film 13 a.

The TD intermeshing rollers 52, 54 can form thick regions or thickerribs 44 a, thinner webs 46 a, and bonds 49 a in the films 10, 10′. Inone or more implementations, the adjacent thick ribs 44 a of the films10, 10′ can be joined by bonds 49 a. In addition to forming ribs 46 a,44 a and bonds 49 a, TD ring rolling the films 10, 10′ can increase orotherwise modify one or more of the tensile strength, tear resistance,impact resistance, or elasticity of the films 10, 10′, in addition towhatever additional strength is provided by the partially discontinuousbonds 49 a between adjacent layers.

To the extent that TD or other ring rolling is used to bond the films10, 10′, the ribbed pattern 36 a (e.g., width and spacing of the ribs 46a, 44 a) can depend on the pitch 32 a of the ridges 56, 58, the DOE 34a, and other factors. As portions of the films 10, 10′ including aribbed pattern 36 a also represent areas of the multi-layer film inwhich the adjacent layers are non-continuously bonded to one another, itwill be apparent that altering the spacing and/or width of ribs 46 a, 44a can affect the overall strength of the film. For example, providingmore bonded surface area relative to the unbonded surface area canincrease the density of such bonds 49 a that can absorb forces,increasing the film strength.

FIG. 5D further illustrates that the bonds 49 a can bond thick linearribs 44 a of the layers 10, 10′ together. In particular, the bonds 49 acan be coextensive and aligned with opposing thicker ribs 44 a and bondthem together. FIG. 5D illustrates that the bonds 49 a can secure some,but not all, of the thick linear ribs 44 a of one layer to the thicklinear ribs 44 a of an adjacent layer. In particular, FIG. 5Dillustrates that bonds 49 a can secure every other thick linear rib 44 aof adjacent layers together. The unbounded thicker ribs 44 a can formunbounded regions 45. In alternative implementations, bonds 49 a cansecure each thick linear rib 44 a of adjacent layer together.

FIG. 6 illustrates a top view of the TD incrementally-stretched andincrementally-bonded multi-layer film 13 a. As shown by FIG. 6, themulti-layer film 13 a includes thicker ribs 44 a bonded together to formbonded regions 49 a adjacent to thinner regions 46 a that form un-bondedregions 47 a with bonded regions 46 a and adjacent un-bonded regions 44a. Similar to MD ring rolling, TD ring rolling the thermoplastic filmscan result in relatively light, partially discontinuous bonding ofadjacent layers 10 c, 10 c′, increasing the strength of the multi-layerfilm 13 a.

FIG. 6 illustrates that the bonded regions 49 a can include stripes thatextend across the multi-layer film 13 a in the machine direction. Asshown by FIG. 6, the stripes or bonded regions 49 a can extend acrossthe entire width of the multi-layered lightly-laminated film 15 b. Inalternative implementations, bonded regions 49 a can extend across onlya portion of the multi-layer film 13 a. Similar to MD ring rolling, thepitch and the DOE of the ridges 56, 58 of the intermeshing rollers 52,54 can affect the width and spacing of the stripes or bonded regions 49a, as well as the strength of the light bonds formed between adjacentlayers, thereby affecting the overall increase in strength provided bythe processing.

Additionally, the bonded regions 49 a and thicker ribs 44 a can bevisually distinct from the un-bonded regions 47 a and thinner regions 46a as a result bring the inner and outer layers 10, 10′ in direct contactas described above. One will appreciate that the size of the uppersurfaces of the ridges 56, 58 can dictate the visibility of anyvisually-distinct regions created by the TD ring rolling. For example,in one or more embodiments bonded regions 49 a with a width less than1/16th of an inch may be somewhat difficult to detect or see. As such,in one or more embodiments the upper surfaces of the ridges 56, 58 canhave a width equal to or greater than about 1/16th. In particular, inone or more embodiments the upper surfaces of the ridges 56, 58 can havea width of between about 1/16th of an inch and about 1 inch. In otherembodiments, the bonded regions 49 a can purposefully have a width lessthan 1/16th an inch.

Referring to FIG. 6, the dotted areas/shaded areas of the multi-layerfilm 13 a can have a metallic or other unexpected appearance, while thenon-dotted areas (in this case stripes) can have the appearance/color ofpigmented inner layer 10′. For example, when the pigmented film 10′ isblack, the dotted areas/shaded areas can have a silvery or grey metallicappearance while the non-dotted areas have a black appearance.

In still further implementations, one or more of the layers 10, 10′ canundergo both an MD ring rolling process and a TD ring rolling process tocreate the multi-layer film with a metallic appearance and optionallyvisually-distinct regions. For example, FIG. 7A illustrates a top viewof a MD & TD incrementally-stretched and incrementally-bondedmulti-layer film 13 b. The multi-layer film 13 b includes thicker ribs44 b, 44 c bonded together to form bonded regions 49 b, 49 c adjacent tothinner regions 46 b that form un-bonded regions 47 b. The multi-layerfilm 13 b can have a grid pattern 36 b including alternating series ofun-bonded regions 47 b and bonded regions 49 b, 49 c. In particular,un-bonded regions 47 b may comprise a plurality of discrete squares orrectangles while the remainder of the surface comprises a grid ofhorizontal and vertical bonded regions that are connected together. Thebonded regions 49 b, 49 c can include stripes 49 b that extend along themulti-layer film 13 b in the machine direction, and stripes 49 c thatextend along the film in the transverse direction, which cross eachother. As shown by FIG. 7A, in one or more implementations, the aspectratio of the rows and columns of the bonded regions 49 b, 49 c can beapproximately 1 to 1. In alternative implementations, the aspect ratioof the rows and columns of bonded regions 49 b, 49 c can be greater orless than 1 to 1, for example, as explained in greater detail inrelation to FIG. 13.

The multi-layer film 13 b with bonded regions and adjacent un-bondedregions created by MD and TD ring rolling can allow for greater materialsavings by further increasing the surface area of a given portion offilm, by increasing the density of light lamination bonds within a givenarea, and may also provide properties or advantages not obtained by MDor TD ring rolling alone.

Additionally, the bonded regions 49 b, 49 c and thicker ribs 44 b, 44 ccan be visually distinct from the un-bonded regions 47 b and thinnerregions 46 b as a result bring the inner and outer layers 10, 10′ indirect contact as described above. One will appreciate that the size ofthe upper surfaces of the ridges 24, 26, 56, 58 can dictate thevisibility of any visually-distinct regions created by the MD ringrolling. For example, in one or more embodiments bonded regions 49 b, 49c with a width less than 1/16th of an inch may be somewhat difficult todetect or see. As such, in one or more embodiments the upper surfaces ofthe ridges 24, 26, 56, 58 can have a width equal to or greater thanabout 1/16th. In particular, in one or more embodiments the uppersurfaces of the ridges 24, 26, 56, 58 can have a width of between about1/16th of an inch and about 1 inch. Furthermore, the ridges 24, 26 ofthe MD ring rollers 12, 14 can have a different width than the ridges56, 58 of the TD ring rollers 52, 54. In such implementations, thestripes 49 c may be more visibly-distinct than the stripes 49 b or viceversa.

The dotted areas/shaded areas of the multi-layer film 13 b can havemetallic appearance, while the non-dotted areas (in this case stripes)can have the appearance/color of pigmented inner layer 10′. For example,when the pigmented film 10′ is black, the dotted areas/shaded areas canhave a silvery or grey metallic appearance while the non-dotted areashave a black appearance.

FIG. 7A illustrates a multi-layer film 13 b in which both the outerlayer 10 and the inner layer 10′ passed together through the MD ringrollers 12, 14 and the TD ring rollers 52, 54. In alternativeembodiments, one of the outer layer 10 and the inner layer 10′ can passthrough one of the MD or TD ring rollers separately prior to the films15 passing together through the other of the MD or TD ring rollers. Forexample, FIG. 7B illustrates a multi-layer film 13 b′ in which the outerlayer 10 was MD incrementally-stretched prior to passing together withthe inner layer 10′ through the TD ring rollers 52, 54 to TDincrementally-stretched and discontinuously bonded to the layers 15together. As shown, the MD extending stripes 44 b can have a metallicappearance while the TD extending stripes 44 c have an appearance/colorof the inner layer 10′. Furthermore, the intersection of the MDextending stripes 44 b and the TD extending strips 44 c can be visuallydistinct from the rest of the TD extending stripes 44 c such the film 13b′ has a stitched appearance.

In yet further implementations, a manufacturer can use diagonal orhelical (DD) ring rolling. DD ring rolling processes (and associated DDintermeshing rollers) can be similar to the MD ring rolling process (andassociated MD intermeshing rollers 12, 14) described herein above,except that the ridges and grooves of the DD intermeshing rollers canextend at an angle relative to the axes of rotation. In particular, theridges and grooves of the DD ring rollers can extend at an angle ofbetween about 15 degrees and about 75 degrees relative to the axes ofrotation (or the MD or TD directions). FIG. 8 illustrates a DDincrementally-stretched and incrementally-bonded multi-layer film 13 cformed by bonding two films together by passing the films through DDring rollers. As shown the multi-layer film 13 c can have a diamondpattern 36 c. The diamond pattern 36 c can include alternating series ofdiamond-shaped thinner regions 46 c defining un-bonded areas or regions47 c and thicker ribs 44 a secured by bonds to form bonded regions 49 d.

The bonded regions can include stripes 49 d oriented at an anglerelative to the transverse direction such that the stripes 49 d areneither parallel to the transverse or machine direction. The illustratedconfiguration may be achieved with two ring rolling operations, similarto that of FIG. 7A, but in which the DD ring rollers of each operationare angularly offset relative to one another (e.g., one providing anangle of about 45° off of MD ring rolling, the other providing an angleof about 45° off of TD ring rolling). One will appreciate that DD ringrolling the film can biaxially orient the thinner, stretched regions 46c. In particular, orient the thinner, stretched regions 46 c at an angleto the machine direction and the transverse direction. Furthermore, thebonded regions 49 d can be visually-distinct from the non-bonded regions47 c as describe above in relation to the bonded regions 49-49 c andnon-bonded regions 47-47 b.

In accordance with another implementation, a structural elastic likefilm (SELF) process may be used to create a thermoplastic film withstrainable networks, which similarly results in discontinuous bonding ofadjacent layers within a multi-layer film. As explained in greaterdetail below, the strainable networks can include adjacent bonded andun-bonded regions. U.S. Pat. No. 5,518,801; U.S. Pat. No. 6,139,185;U.S. Pat. No. 6,150,647; U.S. Pat. No. 6,394,651; U.S. Pat. No.6,394,652; U.S. Pat. No. 6,513,975; U.S. Pat. No. 6,695,476; U.S. PatentApplication Publication No. 2004/0134923; and U.S. Patent ApplicationPublication No. 2006/0093766 each disclose processes for formingstrainable networks or patterns of strainable networks suitable for usewith implementations of the present invention. The contents of each ofthe aforementioned patents and publications are incorporated in theirentirety by reference herein.

FIG. 9 illustrates a pair of SELF'ing intermeshing rollers 72, 74 forcreating strainable networks with lightly bonded regions in a film. Thefirst SELF'ing intermeshing roller 72 can include a plurality of ridges76 and grooves 78 extending generally radially outward in a directionorthogonal to an axis of rotation 16. Thus, the first SELF'ingintermeshing roller 72 can be similar to a TD intermeshing roller 52,54. The second SELF'ing intermeshing roller 74 can include also includea plurality of ridges 80 and grooves 82 extending generally radiallyoutward in a direction orthogonal to an axis of rotation 20. As shown byFIG. 9, however, the ridges 80 of the second SELF'ing intermeshingroller 74 can include a plurality of notches 84 that define a pluralityof spaced teeth 86.

Referring now to FIG. 10, a multi-layer film 13 d with bonded regionsdispersed about un-bonded regions created using the SELF'ingintermeshing rollers 72, 74 is shown. In particular, as the films 10,10′ pass through the SELF'ing intermeshing rollers 72, 74, the teeth 86can press a portion of the multi-layer web or film out of plane to causepermanent deformation of a portion of the film in the Z-direction. Theportions of the film that pass between the notched regions 84 of theteeth 86 will be substantially unformed in the Z-direction, resulting ina plurality of deformed, raised, rib-like elements 88. The length andwidth of rib-like elements 88 depends on the length and width of teeth86.

As shown by FIG. 10, the strainable network of the multi-layer film 13 dcan include first thicker regions 44 e, second thicker regions 44 f,stretched, thinner transitional regions 46 d connecting the first andsecond thicker regions 44 e, 44 f. The first thicker regions 44 e andthe stretched, thinner regions 46 d can form the raised rib-likeelements 88 of the strainable network. In one or more embodiments, therib-like elements 88 can comprise bonded regions 49 e can bediscontinuous or separated as they extend across the multi-layered film15 e in both transverse and machine directions. This is in contrast tostripes that extend continuously across a film in one of the machine ortransverse directions.

The rib-like elements 88 can allow the multi-layered lightly-laminatedfilm 15 e to undergo a substantially “geometric deformation” prior to a“molecular-level deformation.” As used herein, the term “molecular-leveldeformation” refers to deformation, which occurs on a molecular leveland is not discernible to the normal naked eye. That is, even though onemay be able to discern the effect of molecular-level deformation, e.g.,elongation or tearing of the film, one is not able to discern thedeformation, which allows or causes it to happen. This is in contrast tothe term “geometric deformation,” which refers to deformations ofmulti-layered lightly-laminated film 15 e which are generallydiscernible to the normal naked eye when the multi-layered film 15 e orarticles embodying the multi-layer film 13 d are subjected to an appliedstrain. Types of geometric deformation include, but are not limited tobending, unfolding, and rotating.

Thus, upon application of strain, the rib-like elements 88 can undergogeometric deformation before either the rib-like elements 88 or the flatregions undergo molecular-level deformation. For example, an appliedstrain can pull the rib-like elements 88 back into plane with the flatregions prior to any molecular-level deformation of the multi-layer film13 d. Geometric deformation can result in significantly less resistiveforces to an applied strain than that exhibited by molecular-leveldeformation.

In addition to improved properties thus provided by the ability togeometrically deform, the SELF'ing process also discontinuously andlightly laminates adjacent layers of the multi-layer film together,providing the benefits noted above. In particularly, the film layers 10,10′ can be lightly laminated at regions 49 e, but un-bonded at regions47 d. The strength of the lamination bond is relatively weak, so as tobe less than the weakest tear resistance of the individual layers of themulti-layer film. Thus, the lamination bond is broken rather than theindividual layer tearing upon application of a force. Typically, tearingin the MD direction requires less applied force than tearing in the TDdirection, thus in one embodiment, the lamination bond strength is lessthan the MD tear resistance of each individual layer of the multi-layerfilm.

FIG. 11 illustrates a multi-layer film 13 e with a strainable network ofrib-like elements 88 a arranged in diamond patterns. The strainablenetwork of the multi-layer film 13 e can include first thicker regions44 e, second thicker regions 44 f, stretched, thinner transitionalregions 46 d connecting the first and second thicker regions 44 e, 44 f.The first thicker regions 44 e and the stretched, thinner regions 46 dcan form the raised rib-like elements 88 a of the strainable network. Inone or more embodiments, the rib-like elements 88 a can comprise bondedregions 49 e. Furthermore, the bonded regions 49 e can bevisually-distinct from the non-bonded regions 47 d as describe above inrelation to the bonded regions 49-49 c and non-bonded regions 47-47 b.

One or more implementations of the present invention can includestrainable network patterns other than those shown by FIGS. 10 and 11,or combinations of various patterns. It should be understood that theterm “pattern” is intended to include continuous or discontinuoussections of patterns, such as may result, for example, from theintersection of first and second patterns with each other. Furthermore,the patterns can be aligned in columns and rows aligned in the machinedirection, the transverse direction, or neither the machine nortransverse directions.

One will appreciate in light of the disclosure herein that using ringrolling and/or SELFing to form the light bonds can provide theadditional benefit of stretching the film layers, thereby reducing thebasis weight of the multi-layered lightly-laminated film. Thus, usingincremental stretching to form the light bonds can allow for multi-layerfilms at a lower basis weight (amount of raw material) to perform thesame as or better than higher basis weight mono-layer or co-extrudedfilms.

Additionally or alternatively to ring rolling and SELFing, one or moreimplementations include using embossing, stamping, adhesive lamination,ultrasonic bonding, or other methods of laminating layers of amultilayer film or creating visually-distinct areas by bringing an outerlayer 10 into direct contact with an inner layer 10′. In suchimplementations, one or more of the layers of the multi-layer film canbe stretched to reduce the basis weight and/or modify the strengthparameters of the film prior to lamination. Stretching of the individuallayers can include incrementally-stretching (e.g., ring rolling,SELFing) or continuous stretching (e.g., MDO).

FIGS. 12A-12C illustrate an embossing type roll configuration forlightly bonding and/or forming visually-discrete areas by passing twofilms through a set of intermeshing rollers including a punch roll 71and a cooperating die roll 73, where the punch roll is provided withpunch regions 77 and the die roll is provided with corresponding dieregions 75 for cooperating with the punch regions 77. The punch regions77 may each have a plurality of punch elements 81 for cooperating withcorresponding die elements 79 in the die regions 75. Cooperatingengagement of the punch elements 81 with the die elements 79, with asheet material therebetween, forms a bonded pattern on the material.Alternatively, the cooperating die roll 73 may comprise a conformablesurface for conforming to the punch elements 81, or other surfaceconfiguration of the punch roll 71.

Referring to FIG. 12C, a pattern formed by the rolls 71, 73 isillustrated in which each of the bonded areas 49 f of the laminate isformed by a cooperating set of punch and die elements 79, 81, and theremaining unformed areas define the un-bonded areas 47 e of themulti-layer film with the unexpected appearance.

One will appreciate in light of the disclosure herein that using ringrolling and/or SELFing to form the light bonds can provide theadditional benefit of stretching the film layers, thereby reducing thebasis weight of the multi-layered lightly-laminated film. Thus, usingincremental stretching to form the light bonds can allow for multi-layerfilms at a lower basis weight (amount of raw material) to perform thesame as or better than higher basis weight mono-layer or co-extrudedfilms.

As discussed in detail above, implementations of the present inventioninvolve forming multi-layered films with unexpected appearances and thenforming visually-distinct areas in such films by bringing the individualfilm layers into intimate contact. The following examples describevarious exemplary multi-layered films with unexpected appearances.

EXAMPLES Example A

Control. A continuously laminated two ply film was created by overlayinga 0.5 mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film with 2.5 mil tall ribs spaced approximately 400 milsapart (formed by extruding the film in a ribbed pattern) andcontinuously laminating the films together by coextrusion. The laminatedfilm A had a black appearance as shown in Table I.

Example B

A discontinuously laminated two ply film was created by overlaying a 0.5mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film and laminating the films together discontinuousadhesive lamination. The laminated film B had a slightly silver metallicappearance as shown in Table I.

Example C

A discontinuously laminated two ply film was created by overlaying a 0.5mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film and laminating the films together by MD ring rollingat 430 DOE with a 400 pitch tool. The laminated film C had a more silvermetallic appearance as shown in Table I.

Example D. A discontinuously laminated two ply film was created byoverlaying a 0.5 mil, 0.920 density LLDPE, un-stretched, black filmcontaining 4.8% carbon black with a 0.5 mil, 0.920 density LLDPE,un-stretched, un-pigmented film with 2.5 mil tall ribs spacedapproximately 0.40 inches apart (formed by extruding the film in astretched ribbed pattern) and laminating the films together by MD ringrolling at 430 DOE with a 400 pitch tool. The laminated film D had amore silver metallic appearance and shown in Table I.

Example E

A discontinuously laminated two ply film was created by overlaying a 0.5mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film with 2.5 mil tall ribs spaced approximately 0.40inches apart (formed by extruding the film in a ribbed pattern) andlaminating the films together by TD ring rolling at 20 DOE with a 40pitch tool. The laminated film E had a more silver metallic appearanceand shown in Table I.

Example F

A discontinuously laminated two ply film was created by overlaying a 0.5mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film with 2.5 mil tall ribs spaced approximately 0.40inches apart (formed by extruding the film in a ribbed pattern), theun-pigmented film then stretched by MD ring rolling at 430 DOE with a400 pitch tool and laminating the films together by TD ring rolling at20 DOE with a 40 pitch tool. The laminated film F had a silveryappearance and shown in Table I.

Example G

A discontinuously laminated two ply film was created by overlaying a 0.5mil, 0.920 density LLDPE, un-stretched, black film containing 4.8%carbon black with a 0.5 mil, 0.920 density LLDPE, un-stretched,un-pigmented film with 2.5 mil tall ribs spaced approximately 0.40inches apart (formed by extruding the film in a ribbed pattern), theun-pigmented film then stretched by MD ring rolling at 430 DOE with a400 pitch tool and laminating the films together the discontinuousapplication of adhesive. The laminated film F had a silvery appearanceand shown in Table I.

TABLE I Appearance Multi-ply Film Black = 0 Un-Pigmented on SilverPigmented Description Metallic = 4 Example A - Pigmented - Unstretched 0Control Un-Pigmented - Unstretched Continuous lamination Example BPigmented - Unstretched 1 Un-Pigmented - Unstretched DiscontinuousUn-Stretched lamination Example C Pigmented - Unstretched 2Un-Pigmented - Unstretched Discontinuous Stretched lamination Example DPigmented - Unstretched 3 Un-Pigmented - Unstretched, non-FlatDiscontinuous Stretched lamination Example E Pigmented - Unstretched 3Un-Pigmented - Unstretched, non-Flat Discontinuous Stretched laminationExample F Pigmented - Unstretched 4 Un-Pigmented - StretchedDiscontinuous Stretched lamination Example G Pigmented - Unstretched 4Un-Pigmented - Stretched Discontinuous Un-Stretched lamination

The Examples in Table I show that a multi-ply film resulting from thediscontinuous lamination of an un-pigmented ply to a pigmented ply,where the un-pigmented ply has been cold stretched by prior to or duringlamination, will have a noticeably metallic appearance.

One will appreciate in light of the disclosure herein that themulti-layered films with the unexpected appearances andvisually-distinct areas can form part of any type of product made from,or incorporating, thermoplastic films. For instance, grocery bags, trashbags, sacks, packaging materials, feminine hygiene products, babydiapers, adult incontinence products, sanitary napkins, bandages, foodstorage bags, food storage containers, thermal heat wraps, facial masks,wipes, hard surface cleaners, and many other products can includelightly bonded multi-layer films to one extent or another. Trash bagsand food storage bags may be particularly benefited by the films andmethods of the present invention.

Referring to FIG. 13, in a particular implementation of the presentinvention, the multi-layer film 13 with a unique appearance illustratedin FIG. 4 may be incorporated in a bag construction, such as a flexibledraw tape bag. The multi-layered bag 100 can include a bag body formedfrom a piece of incrementally-stretched multi-layered film folded uponitself along a bag bottom 94. Side seals 93 and 95 can bond the sides96, 98 of the bag body together to form a semi-enclosed container havingan opening 90 along an upper edge 102. The bag 100 also optionallyincludes closure means 104 located adjacent to the upper edge 102 forsealing the top of the bag 100 to form a fully-enclosed container orvessel. The bag 100 is suitable for containing and protecting a widevariety of materials and/or objects. The closure means 104 can compriseflaps, adhesive tapes, a tuck and fold closure, an interlocking closure,a slider closure, a zipper closure or other closure structures known tothose skilled in the art for closing a bag. For example, FIG. 13illustrates a draw tape 104 enclosed within the upper portion of the bag100 by a hem seal 91.

Furthermore, a bag 100 formed from a multi-layereddiscontinuously-laminated film can have a first or outer layer ofthermoplastic material. The first layer can include first and secondside walls joined along a bottom edge, a first side edge, and anopposing second side edge. In particular, the bottom edge of the firstlayer can comprise a fold. The bag 100 can also include a second orinner layer of thermoplastic material. The second layer can includeincluding first and second side walls joined along a bottom edge, afirst side edge, and an opposing second side edge. The second layer ispositioned within the first layer. Furthermore, the first and the secondlayer are lightly bonded to each other and incrementally stretched. Thefirst or outer layer comprises a clear or transparent layer. The inneror second layer comprises a pigmented layer.

As shown, the sides of the bag body can include two film layers withthicker regions 44 that are bonded 49 and stretched regions 46 that areun-bonded. Both the bonded, thicker regions 44, 49 and the stretched,unbounded regions 46, 47 can form of stripes. The stripes can extendacross the multi-layered bag 100 in the TD direction, or in other words,from the bottom 94 of the bag 100 toward the top 102. The multi-layeredbag 100 can require less material to form than an identical bag formedwith film of the same thermoplastic material. Additionally, despiterequiring less material, the multi-layered bag 100 includes improvedstrength properties imparted by lightly bonding adjacent layers of themulti-layer film together. As the bonded regions 49 are areas in whichthe inner layer is in intimate contact with the outer layer, the bondedregions 49 can be visually-distinct from unbounded areas 47 of the bag100. In other words, the unbounded areas 46 can have a unique appearanceor in other words and appearance that differs from that the innerpigmented layer and the outer substantially un-pigmented layer. Asmentioned previously, in one or more embodiments the unique appearanceis a metallic appearance. The visually-distinct bonded areas 49 can havethe appearance of the inner pigmented layer. For example, when the innerpigmented-layer comprises black, the visually-distinct bonded areas 49can have a black appearance.

FIG. 13 further illustrates that the side seals 93, 95 can also bevisually distinct. In particular, the side seals can have the appearanceof the inner pigmented-layer and thus be visually distinct from a mainbody of the bag 100. As shown by FIG. 13, because the bonded areas 49may comprise thin stripes the body of the bag 100 may have an appearancesubstantially that of the unique appearance. For example, in one or moreembodiments the main body of the bag 100 can have a metallic appearance.Thus, the side seals 93, 95 can visually stand out compared to the restof the bag 100. As shown by FIG. 13, in one or more embodiments the sideseals can have an increased width compared to conventional side seamsand can thus function as an aesthetic feature. For example, in one ormore embodiments the side seams 93, 95 can have a width of between1/16th an inch and one inch. In particular, the side seams 93, 95 canhave a width of 1/16th an inch, ⅛th an inch, ¼th an inch, ½ an inch, ¾than inch, or 1 inch.

FIG. 14 illustrates a multi-layered tie bag 100 a incorporating amulti-layered film in accordance with an implementation of the presentinvention. As shown, the sides of the tie bag 100 a can include apattern of un-bonded, regions 47 f and bonded regions 49, 49 a createdby MD and TD ring rolling. The bonded regions can include stripes thatextend across the bag 100 a in the machine direction. Additionally, thebonded regions can include stripes that extend across the bag 100 a inthe transverse direction, or in other words from the bag bottom 94 toflaps 110 of an upper edge 112 of the multi-layered bag 100 a. Bondedregions 49, 49 a are characterized by relatively light bonding ofadjacent layers of the multi-layer film, which acts to absorb forcesinto breaking of the lamination bond rather than allowing that sameforce to cause tearing of either of the layers of the multi-layer film.Such action provides significantly increased strength to the multi-layerfilm as compared to a monolayer similar thickness film or compared to amulti-layer film of similar thickness where the layers are stronglybonded together (i.e., at a bond strength at least as great as the tearresistance of the weakest layer). The lamination bond includes a bondstrength that is advantageously less than the tear resistance of each ofthe individual films so as to cause the lamination bond to fail prior totearing of the film layers.

In comparison with the film 13 b of FIG. 7, the spacing between the MDextending thicker ribs or regions 44 a are greater in the multi-layeredbag 100 a. Using MD ring rolls having a greater pitch between ridgescreates this effect. Similarly, the spacing of the TD extending thickerribs 44 is greater in the multi-layered bag 100 a than the multi-layeredfilm 13 b. Using TD ring rolls having a greater pitch between ridgescreates this effect. Furthermore, the relative spacing between the MDextending stripes and the TD extending stripes differs in themulti-layered bag 100 a, while relative spacing is the same in themulti-layered film 13 b. This effect is created by using TD ring rollshaving a greater pitch between ridges compared to the pitch betweenridges of the MD ring rolls. Similar to the bag 100, the bonded regions49 a, 49 can comprise areas of intimate contact between an outersubstantially un-pigmented layer and an inner pigmented-layer. Thus, thebonded regions 49 a, 49 can be visually-distinct from the unboundedregions 47 f of the bag 100 a.

FIG. 14 further illustrates that the bag 100 a can includevisually-distinct side seals 93 a, 95 a. In particular, FIG. 14illustrates that the side seals 93 a, 95 a comprise a serpentinepattern. In alternative embodiments, the side seals can comprise otherpatterns. In any event, one will appreciate that a manufacturer cancreate visually-distinct and side seals to provide an aesthetic designto the bag 100 a.

In addition to the varying the pattern of visually-distinct regions in abag or film, one or more implementations also include providingvisually-distinct regions in certain sections of a bag or film. Forexample, FIG. 15 illustrates a multi-layered bag 100 b having an uppersection adjacent a top hem seal 91 that comprises a region in which theinner pigmented and outer substantially un-pigmented layers are inintimate contact providing the upper area with a visually-distinctappearance. Similarly, the multi-layered bag 100 b includes a bottomsection adjacent a bottom fold or edge 94 in which the inner pigmentedand outer substantially un-pigmented layers are in intimate contactproviding the bottom section with a visually-distinct appearance.

A middle section 204 of the multi-layered bag 100 b between the upperand lower sections on the other hand can include discontinuousvisually-distinct regions. In particular, FIG. 15 illustrates that themiddle section can include a strainable network of rib-like elementsarranged in diamond patterns similar to the multi-layered film 13 e ofFIG. 11. Thus, the middle section 204 of the multi-layered bag 100 b caninclude improved properties, such as elasticity and impact resistance,created by the strainable network. Furthermore, the visually-distinctregions (i.e., the stretched transitional regions of the rib-likeelements) can serve to notify a consumer of that the middle sectionincludes improved properties.

FIG. 15 further illustrates that the side seals 93, 95 can also bevisually distinct. In particular, the side seals can have the appearanceof the inner pigmented-layer and thus be visually distinct from a mainbody of the bag 100 b. As shown by FIG. 15, because the bonded areas 49e may comprise two layers in intimate contact and the side seals cancomprise four or more layers, the side seals 93, 95 can have anappearance that differs from the bonded areas 49 e and the upper andlower areas. For example, the side seals 93, 95 can comprise a darkershades of the color of the pigmented inner-layer.

One will appreciate in light of the disclosure herein that amanufacturer can include decorative visually-distinct regions in theside seals or other regions of a bag by brining the inner pigmented andthe outer substantially un-pigmented layers into intimate contact. Forexample, FIG. 16 illustrates a draw string bag 100 c including aplurality of visually-distinct bonded areas 49 f interspersed amongunbounded areas 47 e.

Thus, one will appreciate in light of the disclosure herein that amanufacturer can tailor specific sections or zones of a bag or film withdesirable properties by MD, TD, DD ring rolling, SELF'ing, orcombinations thereof. One will appreciate in light of the disclosureherein that one or more implementations can include visually-distinctregions arranged in other patterns/shapes. Such additional patternsinclude, but are not limited to, intermeshing circles, squares,diamonds, hexagons, or other polygons and shapes. Additionally, one ormore implementations can include visually-distinct regions arranged inpatterns that are combinations of the illustrated and describedpatterns/shapes.

One or more implementations of the present invention can also includemethods of forming multi-layered films and bags having a uniqueappearance and visually-distinct regions. FIGS. 17-22 and theaccompanying description describe such methods. Of course, as apreliminary matter, one of ordinary skill in the art will recognize thatthe methods explained in detail herein can be modified. For example,various acts of the method described can be omitted or expanded,additional acts can be included, and the order of the various acts ofthe method described can be altered as desired.

FIG. 17 illustrates an exemplary embodiment of a high-speedmanufacturing process 164 for creating multi-layered thermoplasticfilm(s) with the unexpected appearance and then producing multi-layeredplastic bags therefrom with visually-distinct areas. According to theprocess 164, a first thermoplastic film layer 10 and a secondthermoplastic film layer 10′ are unwound from roll 165 a and 165 b,respectively, and directed along a machine direction. Alternatively, thefilm layers 10, 10′ can be directly from one or more extrusion towersrather than stock rolls 165 a, 165 b. The first layer 10 can comprise asubstantially un-pigmented layer and the second layer 10′ can comprise apigmented layer as described above.

The film layers 10, 10′ may pass between first and second cylindricalintermeshing rollers 166, 167 to incrementally stretch and lightlylaminate the initially separate film layers 10, 10′ to create un-bondedregions and bonded regions in at least one section of a multi-layeredlightly-laminated film 168. The intermeshing rollers 166, 167 shown inFIG. 19 have a construction similar to that of intermeshing rollers 12,14 of FIGS. 3A-3B. In other embodiments, the intermeshing rollers 166,167 can have the configuration of any of the other intermeshing rollersshown or described herein. The rollers 166, 167 may be arranged so thattheir longitudinal axes are perpendicular to the machine direction.Additionally, the rollers 166, 167 may rotate about their longitudinalaxes in opposite rotational directions as described in conjunction withFIG. 3A. In various embodiments, motors may be provided that powerrotation of the rollers 166, 167 in a controlled manner. As the filmlayers 10, 10′ pass between the first and second rollers 166, 167 theridges and/or teeth of the intermeshing rollers 166, 167 can form amulti-layered film 168 with the unexpected appearance. The first andsecond rollers 166, 167 can also form visually distinct areas bybringing the layers 10, 10′ together into intimate contact. Dependingupon the configuration of the intermeshing rollers 166, 167, suchvisually distinct areas can be readily visible or difficult to see.

During the manufacturing process 164, the multi-layered film 168 canalso pass through a pair of pinch rollers 169, 170. The pinch rollers169, 170 can be appropriately arranged to grasp the multi-layer film 168with the unexpected appearance.

A folding operation 171 can fold the multi-layer film 168 with theunexpected appearance to produce the sidewalls of the finished bag. Thefolding operation 171 can fold the multi-layer film 168 with theunexpected appearance in half along the transverse direction. Inparticular, the folding operation 171 can move a first edge 172 adjacentto the second edge 173, thereby creating a folded edge 174. The foldingoperation 171 thereby provides a first film half 175 and an adjacentsecond web half 176. The overall width 177 of the second film half 176can be half the width 177 of the pre-folded multi-layer film 168 withthe unexpected appearance.

To produce the finished bag, the processing equipment may furtherprocess the folded multi-layer film 168 with the unexpected appearance.In particular, a draw tape operation 178 can insert a draw tape 179 intoends 172, 173 of the multi-layer film 168 with the unexpectedappearance. Furthermore, a sealing operation 180 can form the parallelside edges of the finished bag by forming visually-distinct heat seals181 between adjacent portions of the folded multi-layer film 168 withthe unexpected appearance by bringing the first substantiallyun-pigmented layer 10 into intimate contact with the second pigmentedlayer 10′. The heat seal 181 may strongly bond adjacent layers togetherin the location of the heat seal 181 so as to tightly seal the edges ofthe finished bag. The heat seals 181 may be spaced apart along thefolded multi-layer film 168 with the unexpected appearance to providethe desired width to the finished bags. The sealing operation 180 canform the heat seals 181 using a heating device, such as, a heated knife.

A perforating operation 182 may form a perforation 183 in the heat seals181 using a perforating device, such as, a perforating knife. Theperforations 183 in conjunction with the folded outer edge 174 candefine individual bags 100 e that may be separated from the multi-layerfilm 168 with the unexpected appearance. A roll 185 can wind themulti-layer film 168 with the unexpected appearance embodying thefinished bags 184 for packaging and distribution. For example, the roll185 may be placed into a box or bag for sale to a customer.

In still further implementations, the folded multi-layer film 168 withthe unexpected appearance may be cut into individual bags along the heatseals 181 by a cutting operation. In another implementation, the foldedmulti-layer film 168 with the unexpected appearance may be folded one ormore times prior to the cutting operation. In yet anotherimplementation, the side sealing operation 180 may be combined with thecutting and/or perforation operations 182.

The sealing operation 180 shown in FIG. 17 can be part of a continuous(FIGS. 18A and 18B) or reciprocating (FIG. 19) bag-making process. Asshown in FIG. 18A, a continuous sealing process 180 typically has aninput section 204, a rotary drum 206, and an output section 208. Thefilm plies 202 continuously travel from the input section 204 to therotary drum 206 and then to the output section 208.

The input section generally consists of a driven dancer assembly 210 tocontrol film tension. The rotary drum 206 contains a plurality of heatedseal bars 212 which can press against a sealing blanket 214 to makeseals 230 on the film plies 202. The heated seal bars 212 can only heatthe film plies 202 from one side.

End to end bags are formed with one seal 230 from the drum 206 andside-to-side bags are formed with a pair of seals 230. The drum 206diameter may be adjusted and/or less than all of the seal bars 212turned on to determine the distance between seals 230, and hence, bagsize. The output section 208 generally includes assemblies that act onthe film plies 202 downstream of the seals 230 being formed, such asperforators, winders, folders and the like. The continuous bag makingprocess 180 has the advantage of operating at very high speeds (600ft./min=300 bags/min).

The continuous bag making process 180 can additionally be used to makeboth the side seals 93, 95 and the tape or hem seals 91 described above.Because the tape seals hem seals 91 can involve more plies of materialor different materials compared with the side seals 93, 95, the sealbars 212 can be divided into two individual seal bars. In particular,the seal bars can include a long seal side seal bar 220 and a shortertape seal bar 222, as shown in FIG. 18B. Because the bag may havedifferent plies of material in the side seals 93, 95 and the tape seals91, the side seal bar 220 may have different heating properties from thetape seal bar 222. For example, the tape seal bar 220 may be heated to ahigher temperature to penetrate the additional plies in the tape seals91. Furthermore as shown by FIG. 18C, in one or more embodiments theseal bars can comprise a decorative design. In particular, FIG. 18Cillustrates a serpentine seal bar 212 a used to create the heat seals 93a, 95 a described above in relation to FIG. 14.

Additionally, the heat seal bars 212, 212 a can have a width equal to orgreater than about 1/16th. In particular, in one or more embodiments theheat seal bars 212, 212 a can have a width of between about 1/16th of aninch and about 1 inch. More particularly, the heat seal bars 212, 212 acan have a width of ⅛th an inch, ¼th an inch, ½ an inch, ¾ an inch, etc.The heat seal bars 212, 212 a can form heat seals 93, 95 having acorresponding width. The increased widths of the heat seal bars 212, 212a can allow for the formation of visually noticeable side seals 93, 95.

As shown in FIG. 19, a reciprocating sealing process 180 a typically hasan input section 204, a linear sealing section 205, and an outputsection 208. The input section 204 generally includes of a dancerassembly 210, and a driven nip 211. The film plies 202 are unwoundcontinuously from a roll or during a continuous process and pass throughthe dancer assembly 210 to the driven nip 211. The driven nip 211rotates intermittently, with one cycle of rotation reflecting the widthof one bag. The nip 211 can stop for sealing and the time the nip 211 ismotionless is adjustable as required for downstream operations (such assealing).

The dancer assembly 210, prior to the intermittently operating nip 211and after the continuously operating unwind or process, can gather thefilm plies 202 during the time the nip 211 is not rotating. This canprovide enough film plies 202 to satisfy the requirements of the nip 211when it begins rotating again. Hence, in the input section 204, the filmplies 202 can move in a continuous manner, travel through a dancerassembly 210 that gathers the film plies 202, and through a nip 211 thatoperates in an intermittent manner, converting the film plies 202 motionfrom a continuous motion to an intermittent motion, one bag width at atime.

The linear sealing section 205 of a reciprocating bag making process 180a can include of one or more sealing stations 214 with heated seal bars316 spaced one bag width apart. The heated seal bars 316 can contact thefilm plies 202 each time the film plies 202 motion stops as the filmplies 202 travel in a straight path through the machine. During the filmplies 202 stoppage time, each seal bar 216 (similar to seal bars 212,212 a) on a sealing station 214 can move from a stationary position 218above or below the web to a position which places the seal bar 216 incontact with the film plies 202 from both sides. The seal bar 216 canthen contact the film plies 202 for a period of time as required to makea seal 203. The seal bar 216 can then retract to its original stationaryposition 218, after which the film plies 202 advance intermittently amultiple of one or more bag widths and the process is repeated. One ormore 203. The reciprocating process 180 a has the advantage of longresidence times, heating the film plies from both sides and high qualityseals 203, but can be limited in rate (typically 120 bags/min).

FIG. 20 illustrates another manufacturing process 164 a for producing amulti-layered bag with an unexpected appearance and visually distinctareas. The process 164 a can be similar to process 164 of FIG. 17,except that the film layers 10, 10′ are folded in half to form c-, u-,or j-folded films 15. Thus, in such implementations, the films 10, 10′are unwound from the roll are already folded and inserted together.Methods of forming c-, u-, or j-folded films are described inInternational Patent Application No. PCT/US14/24431 filed Mar. 12, 2014and entitled STOCK ROLLS CONTAINING A FIRST FOLDED FILM WITHIN A SECONDFOLDED FILM AND METHODS OF MAKING THE SAME and U.S. Patent ApplicationPublication No. 2013/0115396. Each of the above-referenced patents andapplications are hereby incorporated by reference in its entirety.

The folded film layers 15 may pass between first and second cylindricalintermeshing rollers 166, 167 to incrementally stretch and lightlylaminate the separate film layers 10, 10′ to create un-bonded regionsand bonded regions in at least one section of a multi-layeredlightly-laminated film. As the film layers 10, 10′ pass between thefirst and second rollers 166, 167 the ridges and/or teeth of theintermeshing rollers 166, 167 can form a multi-layered film with theunexpected appearance. The first and second rollers 166, 167 can alsoform visually distinct areas by bringing the layers 10, 10′ togetherinto intimate contact. Depending upon the configuration of theintermeshing rollers 166, 167, such visually distinct areas can bereadily visible or difficult to see.

In any event, the process 164 a can continue as described above inrelation to FIG. 17 and process 164 to produce finished bag with theunexpected appearance. In particular, a draw tape operation 178 caninsert a draw tape 179 into ends 172, 173 of the multi-layer film 168with the unexpected appearance. Furthermore, a sealing operation 180 canform the parallel side edges of the finished bag by formingvisually-distinct heat seals 181 between adjacent portions of the foldedmulti-layer film 168 with the unexpected appearance by bringing thefirst substantially un-pigmented layer 10 into intimate contact with thesecond pigmented layer 10′. The heat seal 181 may strongly bond adjacentlayers together in the location of the heat seal 181 so as to tightlyseal the edges of the finished bag. The heat seals 181 may be spacedapart along the folded multi-layer film 168 with the unexpectedappearance to provide the desired width to the finished bags. Thesealing operation 180 can form the heat seals 181 using a heatingdevice, such as, a heated knife. A perforating operation 182 may form aperforation 183 in the heat seals 181 using a perforating device, suchas, a perforating knife. The perforations 183 can define individual bags100 e that may be separated from the multi-layer film 168 with theunexpected appearance.

FIG. 21 illustrates yet another manufacturing process 164 b forproducing a multi-layered bag 100 a with an unexpected appearance andvisually distinct areas. The process 164 a can be similar to process 164a of FIG. 20, except that the fold films 15 can pass through a secondset of intermeshing rollers 166 a, 167 a, respectively, after passingthrough intermeshing rollers 166, 167. In one or more embodiments, theintermeshing rollers 166 a, 167 a can comprise SELFing rollers or otherrollers described herein. The intermeshing rollers 166 a, 167 a canfurther stretch and lightly bond at least a portion of the layers of thefold films 15 together and optionally create visually distinct areas asdescribed above.

FIG. 22 illustrates yet another manufacturing process 164 c forproducing a multi-layered bag 100 with an unexpected appearance andvisually distinct areas such as those describe above in relation toExamples F and G. The process 164 c can involve unwinding asubstantially un-pigmented first-film 10 from a first stock roll 165 aand passing the first film 10 through a pair of intermeshing rollers toincrementally stretch the substantially un-pigmented first-film 10.

The process can further involve laminating the substantiallyun-pigmented first-film 10 to a second pigmented film 10′ unwound from asecond stock roll 165 b via a laminating process 177. The laminatingprocess 177 can comprise a discontinuous stretched lamination (e.g., aring rolling process, a selfing process). A discontinuous stretchedlamination process can involve incrementally stretching and bonded thetwo layers 10, 10′ together. Alternatively, the laminating process cancomprise a discontinuous un-stretched lamination process such asadhesive lamination, pressure bonding (e.g., embossing), ultrasonicbonding, corona lamination, and the like).

Accordingly, FIGS. 1A-22 and the corresponding text, therefore,specifically show, describe, or otherwise provide a number of systems,components, apparatus, and methods for forming an intermittingly bondedand stretched multi-layer film with an unexpected appearance andvisually distinct regions.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description.Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.All changes that come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

We claim:
 1. A multi-layer film, comprising: a first substantially un-pigmented thermoplastic film layer comprising a plurality of alternating stretched thinner webs and thicker ribs; a second pigmented thermoplastic film layer comprising a pigment, the second pigmented thermoplastic film layer having an first appearance created by the pigment; a plurality of non-continuous bonds securing the first substantially un-pigmented thermoplastic film layer to the second pigmented thermoplastic film layer; and wherein the multi-layer film, when viewed from the first substantially un-pigmented thermoplastic film layer side comprises: areas having a second appearance differing from the first appearance; and one or more visually-distinct areas having the first appearance.
 2. The multi-layer film as recited in claim 1, wherein the visually-distinct areas comprise areas in which the first substantially un-pigmented thermoplastic film layer and the second pigmented thermoplastic film layer are in intimate contact.
 3. The multi-layer film as recited in claim 2, wherein the visually-distinct areas comprise areas in which in which the first substantially un-pigmented thermoplastic film layer and the second pigmented thermoplastic film layer are heat sealed together.
 4. The multi-layer film as recited in claim 2, wherein the areas having the second appearance comprise areas in which the first substantially un-pigmented thermoplastic film layer and the second pigmented thermoplastic film layer are separated.
 5. The multi-layer film as recited in claim 4, wherein: the pigment is a first color and the first appearance comprises the first color; and the second appearance comprises a second color differing from the first color
 6. The multi-layer film as recited in claim 5, wherein: the first color is a non-metallic color; and the second color is a metallic color.
 7. The multi-layer film as recited in claim 6, wherein: the color is carbon black; the second color is a metallic silver; and the first substantially un-pigmented thermoplastic film layer is transparent.
 8. A multi-layered bag, comprising: a first transparent thermoplastic bag comprising first and second opposing sidewalls joined together along a first side edge, an opposite second side edge, and a closed bottom edge; a second pigmented thermoplastic bag positioned within the first transparent thermoplastic bag, the second pigmented thermoplastic bag comprising third and fourth opposing sidewalls joined together along a first side edge, an opposite second side edge, and a closed bottom edge; a plurality of non-continuous bonds securing the first transparent thermoplastic bag to the second pigmented thermoplastic bag; and wherein the multi-layered bag, when viewed from the outside comprises: one or more visually-distinct areas having a first color of the second pigmented thermoplastic layer; and areas having a second color differing from the first color.
 9. The multi-layered bag as recited in claim 8, wherein the one or more visually-distinct areas comprise a first heat seal securing the first side edge of the first transparent thermoplastic bag to the first side edge of the second pigmented thermoplastic bag; and a second heat seal securing the second side edge of the first transparent thermoplastic bag to the second side edge of the second pigmented thermoplastic bag.
 10. The multi-layered bag as recited in claim 9, wherein the first and the second heat seals have serpentine shapes.
 11. The multi-layered bag as recited in claim 9, wherein the first and second heat seals each have a width of between 1/16th an inch and one inch.
 12. The multi-layered bag as recited in claim 8, wherein the first transparent thermoplastic bag comprises a plurality of alternating stretched thinner webs and thicker ribs.
 13. The multi-layered bag as recited in claim 12, wherein the non-continuous bonds are aligned with the thicker ribs of the first transparent thermoplastic bag.
 14. The multi-layered bag as recited in claim 12, wherein the plurality of non-continuous bonds comprise one of bonds formed from MD ring rolling, bonds formed from TD ring rolling, bonds formed from helical ring rolling, bonds formed from embossing, or bonds formed from SELFing.
 15. The multi-layered bag as recited in claim 8, wherein: the visually-distinct areas comprise areas in which the first transparent thermoplastic bag and the second pigmented thermoplastic bag are in intimate contact; and. the areas having the second color comprise areas in which the first transparent thermoplastic bag and the second pigmented thermoplastic bag are separated.
 16. The multi-layered bag as recited in claim 8, wherein: the first color is a non-metallic color; and the second color is a metallic color.
 17. The multi-layered bag as recited in claim 16, wherein: the color is carbon black; and the second color is a metallic silver.
 18. A method of producing a multi-layer film with an unexpected appearance, comprising: incrementally stretching a first non-pigmented thermoplastic layer; non-continuously bonding a second pigmented thermoplastic layer to the first non-pigmented thermoplastic layer thereby providing a multi-layer film with a first appearance differing from a second appearance of the pigmented layer; and bringing one or more areas of the first non-pigmented thermoplastic layer and the second pigmented thermoplastic layer of the multi-layer film with the first appearance differing from the second appearance of the pigmented layer into intimate contact thereby causing an appearance of the one or more areas to change from the first appearance to the second appearance.
 19. The method as recited in claim 18, wherein bringing one or more areas of the first non-pigmented thermoplastic layer and the second pigmented thermoplastic layer of the multi-layer film with the first appearance differing from the second appearance of the pigmented layer into intimate contact comprises heat sealing portions of the first non-pigmented thermoplastic layer to the second pigmented thermoplastic layer.
 20. The method as recited in claim 18, wherein: incrementally stretching the first non-pigmented thermoplastic layer comprises passing the first non-pigmented thermoplastic layer through a first pair of intermeshing ring rolls; and non-continuously bonding the second pigmented thermoplastic layer to the first non-pigmented thermoplastic layer comprises passing the second pigmented thermoplastic layer and the first non-pigmented thermoplastic layer together through a second pair of intermeshing ring rolls. 